51
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Belli RG, Tafuri VC, Joannou MV, Roberts CC. d0 Metal-Catalyzed Alkyl–Alkyl Cross-Coupling Enabled by a Redox-Active Ligand. ACS Catal 2022. [DOI: 10.1021/acscatal.1c06002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Roman G. Belli
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Victoria C. Tafuri
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Matthew V. Joannou
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey 08903, United States
| | - Courtney C. Roberts
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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52
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Demissie TB, Kessete JM. Mechanistic Studies of the Catalytic Reduction of CO 2 to CO: Efficient CO-Releasing Si- and Ge-Based Catalysts. ACS OMEGA 2022; 7:4694-4702. [PMID: 35155961 PMCID: PMC8829931 DOI: 10.1021/acsomega.1c07142] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
Besides its significant challenges, efficient catalytic conversion of CO2 to value-added chemicals is highly desired. Herein, we report efficient silicon- and germanium-based catalysts for CO2 activation and its reduction to CO studied using B3LYP-GD3/6-31++G(d,p)/tetrahydrofuran (THF) and M06-2X/6-311++g(d,p)/THF density functional theory methods. The catalysts were systematically designed based on the previously reported silicon- and germanium-based compounds. The germanium-based catalysts are reported for the first time in this study. The calculated transition state energy barriers (5.7-15.8 kcal/mol) indicate that all the catalysts can easily activate CO2. Among all the B3LYP-GD3-calculated transition-state energy barriers, the highest energy barrier found (27.2-28.3 kcal/mol) is for the protonation of the carboxylic acid group of the silacarboxylic and germacarboxylic acids. Once the silacarboxylic and germacarboxylic acids are protonated, the water molecule can easily dehydrate and leave the catalysts with CO. The electrochemical reduction of the M-CO (M = Si and Ge) complexes further enhances the complexes to easily release CO, with all transition state energy barriers being lower than 10 kcal/mol. The results show that both CO2 activation and its reduction to CO using the studied catalysts are thermodynamically and kinetically favorable. This work provides an important insight for CO2 activation and its reduction to CO using earth-abundant and nontoxic main group element-based catalysts.
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Affiliation(s)
- Taye B. Demissie
- Department
of Chemistry, University of Botswana, P. Bag 0074, Gaborone 0074, Botswana
| | - Jenbrie M. Kessete
- Department
of Chemistry, Addis Ababa University, Addis Ababa 1176, Ethiopia
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53
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Sajid M, Kaden WE, Kara A. DFT Investigation of Ammonia Formation via a Langmuir-Hinshelwood Mechanism on Mo-Terminated δ-MoN(0001). ACS OMEGA 2022; 7:4277-4285. [PMID: 35155920 PMCID: PMC8830058 DOI: 10.1021/acsomega.1c05967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
In this work, we employed density functional theory to elucidate the energetics associated with elementary steps along a Langmuir-Hinshelwood mechanism for the Haber-Bosch synthesis of ammonia from N2 and H2 on a hexagonal, Mo-terminated molybdenum nitride surface. Using nudged elastic band calculations, we determined the energy barriers involved in the reaction processes. An active site consisting of four nearest-neighbor Mo atoms, previously identified as an active site on similar surfaces, was chosen to investigate the reaction processes. Using this approach, we calculate a barrier of ∼0.5 eV for the dissociation of N2. The superior activity of the dissociation of the strong N2 bonds is rationalized based on the unique geometric and electronic configurations present at these active sites. Despite the favorable energetics for nitrogen dissociation, the energy cost for hydrogenation of NH x (0 ≤ x ≤ 2) species is shown to be energetically limiting for the formation of ammonia through the Langmuir-Hinshelwood mechanism at these sites, with elementary step activation barriers calculated to be as large as ∼2 eV. A comparison to Haber-Bosch results derived from a similar γ-Mo2N model system suggests the relative independence of surface chemistry and bulk stoichiometry for rhombic Mo4 active sites present on molybdenum nitrides.
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Affiliation(s)
- Muhammad Sajid
- Department
of Physics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States
| | - William E. Kaden
- Department
of Physics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States
- Renewable
Energy and Chemical Transformations Cluster, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816, United States
| | - Abdelkader Kara
- Department
of Physics, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States
- Renewable
Energy and Chemical Transformations Cluster, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816, United States
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54
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Chin M, Suh SM, Fang Z, Hegg EL, Diao T. Depolymerization of Lignin via a Microscopic Reverse Biosynthesis Pathway. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Mason Chin
- Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
| | - Sang Mi Suh
- Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
| | - Zhen Fang
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, Room 313A, East Lansing, Michigan 48824, United States
| | - Eric L. Hegg
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, Room 313A, East Lansing, Michigan 48824, United States
| | - Tianning Diao
- Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
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55
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Frye CW, Egger DT, Kounalis E, Pearce AJ, Cheng Y, Tonks IA. α-Diimine synthesis via titanium-mediated multicomponent diimination of alkynes with C-nitrosos. Chem Sci 2022; 13:1469-1477. [PMID: 35222931 PMCID: PMC8809399 DOI: 10.1039/d1sc06111a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/26/2021] [Indexed: 01/04/2023] Open
Abstract
α-Diimines are commonly used as supporting ligands for a variety of transition metal-catalyzed processes, most notably in α-olefin polymerization. They are also precursors to valuable synthetic targets, such as chiral 1,2-diamines. Their synthesis is usually performed through acid-catalyzed condensation of amines with α-diketones. Despite the simplicity of this approach, accessing unsymmetrical α-diimines is challenging. Herein, we report the Ti-mediated intermolecular diimination of alkynes to afford a variety of symmetrical and unsymmetrical α-diimines through the reaction of diazatitanacyclohexadiene intermediates with C-nitrosos. These diazatitanacycles can be readily accessed in situ via the multicomponent coupling of Ti[triple bond, length as m-dash]NR imidos with alkynes and nitriles. The formation of α-diimines is achieved through formal [4 + 2]-cycloaddition of the C-nitroso to the Ti and γ-carbon of the diazatitanacyclohexadiene followed by two subsequent cycloreversion steps to eliminate nitrile and afford the α-diimine and a Ti oxo.
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Affiliation(s)
- Connor W Frye
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
| | - Dominic T Egger
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
| | - Errikos Kounalis
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
| | - Adam J Pearce
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
| | - Yukun Cheng
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis Minnesota 55455 USA
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56
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de Graaff S, Schwitalla K, Haaker CV, Bengen N, Schmidtmann M, Beckhaus R. A Niobium Pentafulvene Ethylene Complex: Synthesis, Properties and Reaction Pathways. Dalton Trans 2022; 51:12502-12511. [DOI: 10.1039/d2dt02063g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The π-η5:σ-η1 coordination mode of early transition metal pentafulvene ligands yields a strongly nucleophilic exocyclic carbon atom (Cexo). The substitution of the chlorido ligand of bis(η5:η1-(di-p-tolyl)pentafulvene)niobium chloride (1) by reaction...
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57
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Marchesi S, Nascimbene S, Guidotti M, Bisio C, Carniato F. Application of NMR relaxometry for the real-time monitoring of the removal of metal ions from water by synthetic clays. Dalton Trans 2022; 51:4502-4509. [DOI: 10.1039/d1dt04344g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The removal of paramagnetic metal ions with different charge and ionic radius (i.e. Gd3+, Cu2+, Co2+) from aqueous solutions was carried out by using a Na+-exchanged synthetic saponite clay. Saponite,...
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58
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Furigay MH, Chaudhuri S, Deresh SM, Weberg AB, Pandey P, Carroll PJ, Schatz GC, Schelter EJ. Selective Reduction of Niobium(V) Species to Promote Molecular Niobium/Tantalum Separation. Inorg Chem 2021; 61:23-27. [PMID: 34928141 DOI: 10.1021/acs.inorgchem.1c02976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The critical metals niobium (Nb) and tantalum (Ta) coexist in mineral sources, requiring a separation step to purify the elements from one another. The industrial separation process by solvent extraction uses stoichiometric hydrofluoric acid to manifest differences in the speciation of these otherwise chemically similar elements. The identification of alternative methods to separate Nb/Ta is desirable for fluoride waste reduction. In pursuit of this goal, the novel complexes [Na(CH3CN)3(Et2O)][M((S)-BINOLate)3] [M = Nb (1-Nb), Ta (1-Ta)] were synthesized and characterized. In electrochemical studies, a reduction event at the potential -2.04 V versus ferrocene/ferrocenium was observed for 1-Nb, whereas 1-Ta exhibited no metal-based waves in the electrochemical window. In addition to the inherent 4d/5d orbital energy differences between Nb/Ta, density functional theory calculations suggest a larger degree of π donation from the ligands to the metal cation in 1-Ta compared to 1-Nb, destabilizing the lowest unoccupied molecular orbital. This phenomenon contributes to a calculated reduction potential difference of ca. 0.75 V, allowing for the selective reduction of 1-Nb and separation of the reduction product through leaching with diethyl ether for a separation factor of 6 ± 2.
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Affiliation(s)
- Maxwell H Furigay
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Subhajyoti Chaudhuri
- Department of Chemistry and Graduate Program in Applied Physics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Sean M Deresh
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Alexander B Weberg
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Pragati Pandey
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J Carroll
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - George C Schatz
- Department of Chemistry and Graduate Program in Applied Physics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Eric J Schelter
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
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59
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Shi X, Li S, Reiß M, Spannenberg A, Holtrichter-Rößmann T, Reiß F, Beweries T. 1-Zirconacyclobuta-2,3-dienes: synthesis of organometallic analogs of elusive 1,2-cyclobutadiene, unprecedented intramolecular C-H activation, and reactivity studies. Chem Sci 2021; 12:16074-16084. [PMID: 35024129 PMCID: PMC8672727 DOI: 10.1039/d1sc06052j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/22/2021] [Indexed: 01/25/2023] Open
Abstract
The structure, bonding, and reactivity of small, highly unsaturated ring systems is of fundamental interest for inorganic and organic chemistry. Four-membered metallacyclobuta-2,3-dienes, also referred to as metallacycloallenes, are among the most exotic examples for ring systems as these represent organometallic analogs of 1,2-cyclobutadiene, the smallest cyclic allene. Herein, the synthesis of the first examples of 1-zirconacyclobuta-2,3-dienes of the type [Cp'2Zr(Me3SiC3SiMe3)] (Cp'2 = rac-(ebthi), (ebthi = 1,2-ethylene-1,1'-bis(η5-tetrahydroindenyl)) (2a); rac-Me2Si(thi)2, thi = (η5-tetrahydroindenyl), (2b)) is presented. Both complexes undergo selective thermal C-H activation at the 7-position of the ansa-cyclopentadienyl ligand to produce a new type of "tucked-in" zirconocene system, 3a and 3b, that possesses a η3-propargyl/allenyl ligand. Both types of complexes react with carbonyl compounds, producing enynes in the case of 2a and 2b, as well as η1-allenyl complexes for 3a and 3b. Computational analysis of the structure and bonding of 2a and 3a reveals significant differences to a previously described related Ti complex. All complexes were fully characterised, including X-ray crystallography and experimental results were supported by DFT analysis.
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Affiliation(s)
- Xinzhe Shi
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Sihan Li
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Melanie Reiß
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | | | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
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60
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Sahoo P, Majumdar M. Reductively disilylated N-heterocycles as versatile organosilicon reagents. Dalton Trans 2021; 51:1281-1296. [PMID: 34889336 DOI: 10.1039/d1dt03331j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The reductively disilylated N-heterocyclic systems 1,4-bis(trimethylsilyl)-1-aza-2,5-cyclohexadiene (1Si), 1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (2Si) and its methyl derivatives (3Si and 4Si), and 1,1'-bis(trimethylsilyl)-4,4'-bipyridinylidene (5Si) are proficient organosilicon reagents owing to their low first vertical ionization potentials and the heterophilicity of the polarized N-Si bonds. These have prompted their reactivity as two-electron reductants or reductive silylations. These reactions benefit from the concomitant rearomatization of the N-heterocycles and liberation of trimethylsilyl halides or (Me3Si)2O, which are mostly volatile or easily removable byproducts. In this perspective, we have discussed the utilization of these reductively disilylated N-heterocyclic systems as versatile reagents in the salt-free reduction of transition metals (A) and main-group halides (B), in organic transformations (C) and in materials syntheses (D).
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Affiliation(s)
- Padmini Sahoo
- Department of Chemistry, Indian Institute of Science Education and Research, Pune-411008, Maharashtra, India.
| | - Moumita Majumdar
- Department of Chemistry, Indian Institute of Science Education and Research, Pune-411008, Maharashtra, India.
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61
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Zhizhko PA, Bushkov NS, Pichugov AV, Zarubin DN. Oxo/imido heterometathesis: From molecular stoichiometric studies to well-defined heterogeneous catalysts. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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62
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Kessete JM, Demissie TB, Mohammed AM. Computational mechanistic insights into hafnium catalyzed CO2 activation and reduction. Mol Phys 2021. [DOI: 10.1080/00268976.2021.2003456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Taye B. Demissie
- Department of Chemistry, University of Botswana, Gaborone, Botswana
| | - Ahmed M. Mohammed
- Department of Chemistry, Addis Ababa University, Addis Ababa, Ethiopia
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63
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Platonov DN, Kholodkov DN, Goncharova IK, Belaya MA, Tkachev YV, Dorovatovskii PV, Volodin AD, Korlyukov AA, Tomilov YV, Arzumanyan AV, Novikov RA. Ionic Cyclopropenium-Derived Triplatinum Cluster Complex [(Ph3C3)2Pt3(MeCN)4]2+(BF4–)2: Synthesis, Structure, and Perspectives for Use as a Catalyst for Hydrosilylation Reactions. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Dmitry N. Platonov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Dmitry N. Kholodkov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, 119991, Moscow, Russian Federation
| | - Irina K. Goncharova
- Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospect, 119991 Moscow, Russian Federation
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, 119991, Moscow, Russian Federation
| | - Maria A. Belaya
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Yaroslav V. Tkachev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov st., 119991 Moscow, Russian Federation
| | - Pavel V. Dorovatovskii
- National Research Center “Kurchatov Institute”, 1 Acad. Kurchatov Sq., 123182 Moscow, Russian Federation
| | - Alexander D. Volodin
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, 119991, Moscow, Russian Federation
| | - Alexander A. Korlyukov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, 119991, Moscow, Russian Federation
| | - Yury V. Tomilov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Ashot V. Arzumanyan
- Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospect, 119991 Moscow, Russian Federation
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, 119991, Moscow, Russian Federation
| | - Roman A. Novikov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov st., 119991 Moscow, Russian Federation
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64
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Del Horno E, Jover J, Mena M, Pérez-Redondo A, Yélamos C. Low-Valent Titanium Species Stabilized with Aluminum/Boron Hydride Fragments. Chemistry 2021; 28:e202103085. [PMID: 34735025 DOI: 10.1002/chem.202103085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Indexed: 11/09/2022]
Abstract
Low-valent titanium species were prepared by reaction of [TiCp*X3 ] (Cp*=η5 -C5 Me5 ; X=Cl, Br, Me) with LiEH4 (E=Al, B) or BH3 (thf), and their structures elucidated by experimental and theoretical methods. The treatment of trihalides [TiCp*X3 ] with LiAlH4 in ethereal solvents (L) leads to the hydride-bridged heterometallic complexes [{TiCp*(μ-H)}2 {(μ-H)2 AlX(L)}2 ] (L=thf, X=Cl, Br; L=OEt2 , X=Cl). Density functional theory (DFT) calculations for those compounds reveal an open-shell singlet ground state with a Ti-Ti bond and can be described as titanium(II) species. The theoretical analyses also show strong interactions between the Ti-Ti bond and the empty s orbitals of the Al atom of the AlH2 XL fragments, which behave as σ-accepting (Z-type) ligands. Analogous reactions of [TiCp*X3 ] with LiBH4 (2 and 3 equiv.) in tetrahydrofuran at room temperature and at 85 °C lead to the titanium(III) compounds [{TiCp*(BH4 )(μ-X)}2 ] (X=Cl, Br) and [{TiCp*(BH4 )(μ-BH4 )}2 ], respectively. The treatment of [TiCp*Me3 ] with 4 and 5 equiv. of BH3 (thf) produces the diamagnetic [{TiCp*(BH3 Me)}2 (μ-B2 H6 )] and paramagnetic [{TiCp*(μ-B2 H6 )}2 ] complexes, respectively.
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Affiliation(s)
- Estefanía Del Horno
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805 Alcalá de, Henares-Madrid, Spain
| | - Jesús Jover
- Secció de Química Inorgànica, Departament de Química Inorgànica i Orgànica, Institut de Química Teòrica i Computacional (IQTC-UB), Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Miguel Mena
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805 Alcalá de, Henares-Madrid, Spain
| | - Adrián Pérez-Redondo
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805 Alcalá de, Henares-Madrid, Spain
| | - Carlos Yélamos
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805 Alcalá de, Henares-Madrid, Spain
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65
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Ghana P, Spaniol TP, Okuda J. Scandium Reduced Arene Complex: Protonation and Reaction with Azobenzene. Chem Asian J 2021; 16:3170-3178. [PMID: 34390326 PMCID: PMC8596697 DOI: 10.1002/asia.202100684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/10/2021] [Indexed: 11/10/2022]
Abstract
The reactivity of the reduced anthracene complex of scandium [Li(thf)3 ][Sc{N(tBu)Xy}2 (anth)] (2-anth-Li) (Xy=3,5-Me2 C6 H3 ; anth=C14 H10 2- , thf=tetrahydrofuran) toward Brønsted acid [NEt3 H][BPh4 ] and azobenzene is reported. While a stepwise protonation of 2-anth-Li with two equivalents of [NEt3 H][BPh4 ] afforded the scandium cation [Sc{N(tBu)Xy}2 (thf)2 ][BPh4 ] (3), reduction of azobenzene gave a thermolabile, anionic scandium reduced azobenzene complex [Li(thf)][Sc{N(tBu)Xy}2 (η2 -PhNNPh)] (4), which slowly lost one of the anilide ligands to form the neutral scandium azobenzene complex dimer [Sc{N(tBu)Xy}(μ-η2 :η2 -Ph2 N2 )]2 (5). Exposure of 3 to CO2 produced the scandium carbamate complex [Sc{κ2 -O2 CN(tBu)(Xy)}2 ][BPh4 ] (6) as a result of CO2 insertion into the Sc-N bonds. In an attempt to prepare scandium hydrides, the reaction of 3 with the hydride sources LiAlH4 and Na[BEt3 H] led to the terminal aluminum hydride [AlH{N(tBu)Xy}2 (thf)] (7) and the scandium n-butoxide [Sc{N(tBu)(Xy)}2 (μ-OnBu)] (8) after Sc/Al transmetalation and nucleophilic ring-opening of THF, respectively. All reported compounds isolated in moderate to good yields were fully characterized.
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Affiliation(s)
- Priyabrata Ghana
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Thomas P. Spaniol
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Jun Okuda
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
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Maurer LR, Bursch M, Grimme S, Hansen A. Assessing Density Functional Theory for Chemically Relevant Open-Shell Transition Metal Reactions. J Chem Theory Comput 2021; 17:6134-6151. [PMID: 34546754 DOI: 10.1021/acs.jctc.1c00659] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Due to the principle lack of systematic improvement possibilities of density functional theory, careful assessment of the performance of density functional approximations (DFAs) on well-designed benchmark sets, for example, for reaction energies and barrier heights, is crucial. While main-group chemistry is well covered by several available sets, benchmark data for transition metal chemistry is sparse. This is especially the case for larger, chemically relevant molecules. Addressing this issue, we recently introduced the MOR41 benchmark which covers chemically relevant reactions of closed-shell complexes. In this work, we extend these efforts to single-reference open-shell systems and introduce the "reactions of open-shell single-reference transition metal complexes" (ROST61) benchmark set. ROST61 includes accurate coupled-cluster reference values for 61 reaction energies with a mean reaction energy of -42.8 kcal mol-1. Complexes with 13-93 atoms covering 20 d-block elements are included, but due to the restriction to single-reference open-shell systems, important elements such as iron or platinum could not be taken into account, or only to a small extent. We assess the performance of 31 DFAs in combination with three London dispersion (LD) correction schemes. Further, DFT-based composite methods, MP2, and a few semiempirical quantum chemical methods are evaluated. Consistent with the results for the MOR41 closed-shell benchmark, we find that the ordering of DFAs according to Jacob's ladder is preserved and that adding an LD correction is crucial, clearly improving almost all tested methods. The recently introduced r2SCAN-3c composite method stands out with a remarkable mean absolute deviation (MAD) of only 2.9 kcal mol-1, which is surpassed only by hybrid DFAs with low amounts of Fock exchange (e.g., 2.3 kcal mol-1 for TPSS0-D4/def2-QZVPP) and double-hybrid (DH) DFAs but at a significantly higher computational cost. The lowest MAD of only 1.6 kcal mol-1 is obtained with the DH DFA PWPB95-D4 in the def2-QZVPP basis set approaching the estimated accuracy of the reference method. Overall, the ROST61 set adds important reference data to a sparsely sampled but practically relevant area of chemistry. At this point, it provides valuable orientation for the application and development of new DFAs and electronic structure methods in general.
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Affiliation(s)
- Leonard R Maurer
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Markus Bursch
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Andreas Hansen
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
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Fortier S, Gomez-Torres A. Redox chemistry of discrete low-valent titanium complexes and low-valent titanium synthons. Chem Commun (Camb) 2021; 57:10292-10316. [PMID: 34533140 DOI: 10.1039/d1cc02772g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Titanium is a versatile metal that has important applications in practical synthesis, though this is typically limited to stoichiometric reactions or Lewis acid catalysis. Recently, interest has grown in using titanium and other early-metals for redox catalysis; however, notable limitations exist due to the thermodynamic preference of these metals to adopt high oxidation states. Nonetheless, discrete low-valent titanium (LVT) complexes and their synthons (titanium complexes which chemically behave as LVT sources) are known. Here, we detail the various ligand platforms that are capable of stabilizing LVT compounds and present the redox chemistry of these systems. This includes a discussion of recent developments in the use of LVT synthons for accessing fully reversible oxidative-addition/reductive-elimination reactions.
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Affiliation(s)
- Skye Fortier
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
| | - Alejandra Gomez-Torres
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
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68
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Dodonov VA, Chen W, Liu L, Sokolov VG, Baranov EV, Skatova AA, Zhao Y, Wu B, Yang XJ, Fedushkin IL. Reactions of Iso(thio)cyanates with Dialanes: Cycloaddition, Reductive Coupling, or Cleavage of the C═S or C═O Bond. Inorg Chem 2021; 60:14602-14612. [PMID: 34551514 DOI: 10.1021/acs.inorgchem.1c01581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The dialanes [(dpp-Bian)Al-Al(dpp-Bian)] (1) and [(dpp-dad)Al(THF)-(THF)Al(dpp-dad)] (2) (dpp-Bian = 1,2-[(2,6-iPr2C6H3)NC]2C12H6, dpp-dad = [(2,6-iPr2C6H3)NC(CH3)]2) react with some isothiocyanates, isocyanates, and diphenylketene via [2 + 4] cycloaddition of the C═O or C═S bond across the C═C-N-Al fragment to afford complexes [L(X═C-Y)Al-Al(X═C-Y)L] with an intact Al-Al single bond (3, L = dpp-Bian, X = PhN, Y = O; 4, L = dpp-Bian, X = Ph2C, Y = O; 6, L = dpp-dad, X = BnN, Y = S; 7, L = dpp-dad, X = tBuN, Y = O; 8, L = dpp-dad, X = iPrN, Y = S; and 9, L = dpp-dad, X = CyN, Y = S). A mixed C═N and C═O mode cycloadduct, [(dpp-Bian)(TosN═C-O)Al-Al(TosN-C═O)(dpp-Bian)] 5, was obtained in the reaction of 1 with tosylisocyanate. Heating the solution of 3 resulted in a thermal transformation and a change of the cycloaddition mode from C═O to C═N to give the product [(dpp-Bian)(PhN-C═O)Al(O)Al(PhN-C═O)(dpp-Bian)] 10. The reduction of 7 and 8 with Na yielded the products [Na(THF)n]2[(dpp-dad-H)(X═C-Y)Al]2 (12, X = iPrN, Y = S, n = 2 and 13, X = tBuN, Y = O, n = 3) in which one of the methyl groups of the backbone of the initial dpp-dad ligand was dehydrogenated. When 2 was reacted with the bulky adamantyl isocyanate AdNCO, the C-C coupling of two substrates occurred to form 14 [(dpp-dad)Al(O═C-NAd)2Al(dpp-dad)] in which the coupled dianionic oxamide ligand bridged two Al atoms in a μ,η4-N,O/N,O mode. Moreover, in the presence of 2.0 equiv of Na metal, precursor 2 reacts with tBuNCS, p-TolylNCS, or Me3SiNCO, possibly through the reduced AlI intermediate, to yield the sulfur- or oxygen-bridged dimer [Na(solv)n]2[(dpp-dad)Al(μ-E)]2 (15, E = S, solv = THF, n = 3 and 16, E = O, solv = DME, n = 2) upon C═S or C═O bond cleavage. Dialane 1 reacts with dimethylsulfone to give a Lewis adduct [(dpp-Bian)(Me2SO2)Al]2 (17), which releases dimethylsulfone upon heating. The diamagnetic compounds 3-10 and 12-17 were characterized by NMR and IR spectroscopy. The molecular structures of 3-17 were established by single-crystal X-ray diffraction analysis. Electronic structures of the compounds and possible isomers have been examined by DFT calculations.
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Affiliation(s)
- Vladimir A Dodonov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Weixing Chen
- College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Li Liu
- College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Vladimir G Sokolov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Evgeny V Baranov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Alexandra A Skatova
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Yanxia Zhao
- College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Biao Wu
- College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Xiao-Juan Yang
- College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Igor L Fedushkin
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation.,College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
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69
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Abstract
Titanium is an attractive metal for catalytic reaction development: it is earth-abundant, inexpensive, and generally nontoxic. However-like most early transition metals-catalytic redox reactions with Ti are difficult because of the stability of the high-valent TiIV state. Understanding the fundamental mechanisms behind Ti redox processes is key for making progress toward potential catalytic applications. This Account details recent progress in Ti-catalyzed (and -mediated) oxidative amination reactions that proceed through formally TiII/TiIV catalytic cycles.This class of reactions is built on our initial discovery of Ti-catalyzed [2 + 2 + 1] pyrrole synthesis from alkynes and azobenzene, where detailed mechanistic studies have revealed important factors that allow for catalytic turnover despite the inherent difficulty of Ti redox. Two important conclusions from mechanistic studies are that (1) low-valent Ti intermediates in catalysis can be stabilized through coordination of π-acceptor substrates or products, where they can act as "redox-noninnocent" ligands through metal-to-ligand π back-donation, and (2) reductive elimination processes with Ti proceed through π-type electrocyclic (or pericyclic) reaction mechanisms rather than direct σ-bond coupling.The key reactive species in Ti-catalyzed oxidative amination reactions are Ti imidos (Ti≡NR), which can be generated from either aryl diazenes (RN═NR) or organic azides (RN3). These Ti imidos can then undergo [2 + 2] cycloadditions with alkynes, resulting in intermediates that can be coupled to an array of other unsaturated functional groups, including alkynes, alkenes, nitriles, and nitrosos. This basic reactivity pattern has been extended into a broad range of catalytic and stoichiometric oxidative multicomponent coupling reactions of alkynes and other reactive small molecules, leading to multicomponent syntheses of various heterocycles and aminated building blocks.For example, catalytic oxidative coupling of Ti imidos with two different alkynes leads to pyrroles, while stoichiometric oxidative coupling with alkynes and nitriles leads to pyrazoles. These heterocycle syntheses often yield substitution patterns that are complementary to those of classical condensation routes and provide access to new electron-rich, highly substituted heteroaromatic scaffolds. Furthermore, catalytic oxidative alkyne carboamination reactions can be accomplished via reaction of Ti imidos with alkynes and alkenes, yielding α,β-unsaturated imine or cyclopropylimine building blocks. New catalytic and stoichiometric oxidative amination methods such as alkyne α-diimination, isocyanide imination, and ring-opening oxidative amination of strained alkenes are continuously emerging as a result of better mechanistic understanding of Ti redox catalysis.Ultimately, these Ti-catalyzed and -mediated oxidative amination methods demonstrate the importance of examining often-overlooked elements like the early transition metals through the lens of modern catalysis: rather than a lack of utility, these elements frequently have undiscovered potential for new transformations with orthogonal or complementary selectivity to their late transition metal counterparts.
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Affiliation(s)
- Ian A. Tonks
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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70
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Younas SL, Streuff J. Kinetic Analysis Uncovers Hidden Autocatalysis and Inhibition Pathways in Titanium(III)-Catalyzed Ketone-Nitrile Couplings. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Sara L. Younas
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Jan Streuff
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
- Department of Chemistry—BMC, Uppsala University, Husargatan 3, 75237 Uppsala, Sweden
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71
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Rehbein SM, Kania MJ, Neufeldt SR. Experimental and Computational Evaluation of Tantalocene Hydrides for C–H Activation of Arenes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steven M. Rehbein
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Matthew J. Kania
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Sharon R. Neufeldt
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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72
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Huh DN, Cheng Y, Frye CW, Egger DT, Tonks IA. Multicomponent syntheses of 5- and 6-membered aromatic heterocycles using group 4-8 transition metal catalysts. Chem Sci 2021; 12:9574-9590. [PMID: 34349931 PMCID: PMC8293814 DOI: 10.1039/d1sc03037j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/28/2021] [Indexed: 12/31/2022] Open
Abstract
In this Perspective, we discuss recent syntheses of 5- and 6-membered aromatic heterocycles via multicomponent reactions (MCRs) that are catalyzed by group 4-8 transition metals. These MCRs can be categorized based on the substrate components used to generate the cyclized product, as well as on common mechanistic features between the catalyst systems. These particular groupings are intended to highlight mechanistic and strategic similarities between otherwise disparate transition metals and to encourage future work exploring related systems with otherwise-overlooked elements. Importantly, in many cases these early- to mid-transition metal catalysts have been shown to be as effective for heterocycle syntheses as the later (and more commonly implemented) group 9-11 metals.
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73
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Fostvedt JI, Boreen MA, Bergman RG, Arnold J. A Diverse Array of C-C Bonds Formed at a Tantalum Metal Center. Inorg Chem 2021; 60:9912-9931. [PMID: 34125521 DOI: 10.1021/acs.inorgchem.1c01159] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We demonstrate the formation of a diverse array of organic and organometallic products containing newly formed C-C bonds via successive methyl transfers from di-, tri-, and tetramethyl Ta(V) precursors to unsaturated small molecule substrates under mild conditions. The reactions of Ta(V) methyl complexes 1-X [H2B(MesIm)2]TaMe3X (X = Me, Cl; Im = imidazole, Mes = 2,4,6-trimethylphenyl) with CO led to oxo enolate Ta(V) products, in which the enolate ligands were constructed from Ta-Me groups and two equivalents of CO. Similarly, the reaction of 1-Me with CNXyl yielded an imido enamine Ta(V) product. Surprisingly, 1-Cl reacted with CNXyl (1 equiv) at the borate backbone of the [H2B(MesIm)2] ligand with concomitant methyl transfer from the metal center to form a new, dianionic scorpionate ligand that supported a Ta(V) dimethyl chloro complex (6). Treatment of 1-Cl with further CNXyl led to an azaallyl scorpionate complex, and an imido isocyanide scorpionate complex, along with propene and xylyl ketenimine. Complex 6 reacted with CO to yield a pinacol scorpionate complex 10-a new reaction pathway in early transition metal chemistry. Mechanistic studies revealed that this proceeded via migratory insertion of CO into a Ta-Me group, followed by methyl transfer to form an η2-acetone intermediate. Elimination of acetone furnished a CO-stabilized Ta(III) intermediate capable of rebinding and subsequently coupling two equivalents of CO-derived acetone to form the pinacol ligand in 10.
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Affiliation(s)
- Jade I Fostvedt
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Michael A Boreen
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Robert G Bergman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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74
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Margeson MJ, Seeberger F, Kelly JA, Leitl J, Coburger P, Szlosek R, Müller C, Wolf R. Expedient Hydrofunctionalisation of Carbonyls and Imines Initiated by Phosphacyclohexadienyl Anions. ChemCatChem 2021. [DOI: 10.1002/cctc.202100651] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Matthew J. Margeson
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Felix Seeberger
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - John A. Kelly
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Julia Leitl
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Peter Coburger
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Robert Szlosek
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Christian Müller
- Freie Universität Berlin Institut für Chemie und Biochemie Fabeckstr. 34/36 14195 Berlin Germany
| | - Robert Wolf
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
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75
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Leisering S, Mavroskoufis A, Voßnacker P, Zimmer R, Christmann M. Synthesis of Plakortolides E and I Enabled by Base Metal Catalysis. Org Lett 2021; 23:4731-4735. [PMID: 34096734 DOI: 10.1021/acs.orglett.1c01457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A protecting-group-free synthesis of two endoperoxide natural products, plakortolide E and plakortolide I, is reported. Key steps are a vanadium-mediated epoxidation, an iron-catalyzed allylic substitution, and a cobalt-induced endoperoxide formation. Our approach combines chemoselective bond-forming reactions and one-pot operations to forge an overall efficient synthesis.
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Affiliation(s)
- Stefan Leisering
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Alexandros Mavroskoufis
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Patrick Voßnacker
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Reinhold Zimmer
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Mathias Christmann
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
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76
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Wang X, Cui P, Xia C, Wu L. Catalytic Boration of Alkyl Halides with Borane without Hydrodehalogenation Enabled by Titanium Catalyst. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Xianjin Wang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Penglei Cui
- College of Science Hebei Agricultural University Baoding 071001 P. R. China
| | - Chungu Xia
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
| | - Lipeng Wu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
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77
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Wang X, Cui P, Xia C, Wu L. Catalytic Boration of Alkyl Halides with Borane without Hydrodehalogenation Enabled by Titanium Catalyst. Angew Chem Int Ed Engl 2021; 60:12298-12303. [DOI: 10.1002/anie.202100569] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Indexed: 12/22/2022]
Affiliation(s)
- Xianjin Wang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Penglei Cui
- College of Science Hebei Agricultural University Baoding 071001 P. R. China
| | - Chungu Xia
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
| | - Lipeng Wu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute of LICP Lanzhou Institute of Chemical Physics (LICP) Chinese Academy of Sciences Lanzhou 730000 P. R. China
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78
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Kern C, Selau J, Streuff J. A Titanium-Catalyzed Reductive α-Desulfonylation. Chemistry 2021; 27:6178-6182. [PMID: 33539578 PMCID: PMC8048938 DOI: 10.1002/chem.202005400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/09/2021] [Indexed: 12/14/2022]
Abstract
A titanium(III)-catalyzed desulfonylation gives access to functionalized alkyl nitrile building blocks from α-sulfonyl nitriles, circumventing traditional base-mediated α-alkylation conditions and strong single electron donors. The reaction tolerates numerous functional groups including free alcohols, esters, amides, and it can be applied also to the α-desulfonylation of ketones. In addition, a one-pot desulfonylative alkylation is demonstrated. Preliminary mechanistic studies indicate a catalyst-dependent mechanism involving a homolytic C-S cleavage.
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Affiliation(s)
- Christoph Kern
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Selau
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
| | - Jan Streuff
- Institut für Organische ChemieAlbert-Ludwigs-Universität FreiburgAlbertstr. 2179104Freiburg im BreisgauGermany
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79
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Rumyantsev AV, Pichugov AV, Bushkov NS, Aleshin DY, Strelkova TV, Lependina OL, Zhizhko PA, Zarubin DN. Direct imidation of lactones via catalytic oxo/imido heterometathesis. Chem Commun (Camb) 2021; 57:2625-2628. [PMID: 33587064 DOI: 10.1039/d0cc08274k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report the first examples of direct imidation of lactones giving the corresponding cyclic imidates via oxo/imido heterometathesis with N-sulfinylamines catalysed by a well-defined silica-supported Ti imido complex.
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Affiliation(s)
- Andrey V Rumyantsev
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia. and Department of Chemistry, Moscow State University, Vorob'evy Gory, 1, Moscow 119991, Russia
| | - Andrey V Pichugov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia. and Higher Chemical College, D. Mendeleev University of Chemical Technology of Russia, Miusskaya sq., 9, Moscow 125047, Russia
| | - Nikolai S Bushkov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia. and Department of Chemistry, Moscow State University, Vorob'evy Gory, 1, Moscow 119991, Russia
| | - Dmitry Yu Aleshin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia. and Higher Chemical College, D. Mendeleev University of Chemical Technology of Russia, Miusskaya sq., 9, Moscow 125047, Russia
| | - Tatyana V Strelkova
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia.
| | - Olga L Lependina
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia.
| | - Pavel A Zhizhko
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia.
| | - Dmitry N Zarubin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia.
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80
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Sen N, Khan S. Heavier Tetrylenes as Single Site Catalysts. Chem Asian J 2021; 16:705-719. [DOI: 10.1002/asia.202100038] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/15/2021] [Indexed: 01/16/2023]
Affiliation(s)
- Nilanjana Sen
- Department of Chemistry Indian Institute of Science Education and Research (IISER), Pune Dr. Homi Bhabha Road Pashan, Pune 411008 India
| | - Shabana Khan
- Department of Chemistry Indian Institute of Science Education and Research (IISER), Pune Dr. Homi Bhabha Road Pashan, Pune 411008 India
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81
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Engler H, Lansing M, Gordon CP, Neudörfl JM, Schäfer M, Schlörer NE, Copéret C, Berkessel A. Olefin Epoxidation Catalyzed by Titanium–Salalen Complexes: Synergistic H 2O 2 Activation by Dinuclear Ti Sites, Ligand H-Bonding, and π-Acidity. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Hauke Engler
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Markus Lansing
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Christopher P. Gordon
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Jörg-M. Neudörfl
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Mathias Schäfer
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Nils E. Schlörer
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Albrecht Berkessel
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
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82
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Chen W, Dodonov VA, Sokolov VG, Liu L, Baranov EV, Zhao Y, Fedushkin IL, Yang XJ. Activation of Nitrogen-Rich Substrates by Low-Valent, Redox-Active Aluminum Species. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00738] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Weixing Chen
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Vladimir A. Dodonov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Vladimir G. Sokolov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Li Liu
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Evgeny V. Baranov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Yanxia Zhao
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Igor L. Fedushkin
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Xiao-Juan Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
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83
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Lan S, Liu R, Kong X, Liu J, Luo B, Yang S, Fang X. Ti(O iPr) 4-Facilitated Formal Deoxygenative Annulation of Alkynyl 1,2-Diketones for the Synthesis of Highly Functionalized Furans. Org Lett 2021; 23:1504-1509. [PMID: 33534595 DOI: 10.1021/acs.orglett.1c00291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A unique deoxygenative cyclodimerization of alkynyl 1,2-diketones facilitated by Ti(OiPr)4 is achieved, affording a series of highly functionalized furan products. An unusual C-C bond and C═O bond cleavage of the substrates is observed, and Ti(OiPr)4 plays triplicate roles in the reaction. Furthermore, the products show uncommon fluorescent emission in the solid state, indicating the potential practical applications of this work.
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Affiliation(s)
- Shouang Lan
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Rui Liu
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Xiangwen Kong
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Jinggong Liu
- Orthopedics Department, Guangdong Provincial Hospital of Traditional Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Benlong Luo
- Pingxiang University, Pingxiang 337055, China
| | - Shuang Yang
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
| | - Xinqiang Fang
- State Key Laboratory of Structural Chemistry and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China
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84
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Murugesan K, Donabauer K, König B. Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp 3 )-H Bonds*. Angew Chem Int Ed Engl 2021; 60:2439-2445. [PMID: 33053270 PMCID: PMC7898869 DOI: 10.1002/anie.202011815] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/29/2020] [Indexed: 01/18/2023]
Abstract
The metal-free activation of C(sp3 )-H bonds to value-added products is of paramount importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6-triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal- and cyanide-free conditions. We demonstrate the scope of the method with over 50 examples including late-stage functionalization of drug molecules (celecoxib) and complex structures such as l-menthol, amino acids, and cholesterol derivatives. Furthermore, the presented synthetic protocol is applicable for gram-scale reactions. In addition to methylarenes, selected examples for the cyanation of aldehydes, alcohols and oximes are demonstrated as well. Detailed mechanistic investigations have been carried out using time-resolved luminescence quenching studies, control experiments, and NMR spectroscopy as well as kinetic studies, all supporting the proposed catalytic cycle.
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Affiliation(s)
| | | | - Burkhard König
- Faculty of Chemistry and PharmacyUniversity of RegensburgGermany
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85
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Liu S, Amaro-Estrada JI, Baltrun M, Douair I, Schoch R, Maron L, Hohloch S. Catalytic Deoxygenation of Nitroarenes Mediated by High-Valent Molybdenum(VI)–NHC Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00352] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shenyu Liu
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | | | - Marc Baltrun
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Iskander Douair
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Roland Schoch
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Stephan Hohloch
- University of Innsbruck, Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Innrain 80-82, 6020 Innsbruck, Austria
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86
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Chirik PJ. Looking Forward to 2021: The Fabulous Forties! Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paul J. Chirik
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544 United States
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87
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Bursch M, Hansen A, Pracht P, Kohn JT, Grimme S. Theoretical study on conformational energies of transition metal complexes. Phys Chem Chem Phys 2021; 23:287-299. [PMID: 33336657 DOI: 10.1039/d0cp04696e] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Conformational energies are an important chemical property for which a performance assessment of theoretical methods is mandatory. Existing benchmark sets are often limited to biochemical or main group element containing molecules, while organometallic systems are generally less studied. A key problem herein is to routinely generate conformers for these molecules due to their complexity and manifold of possible coordination patterns. In this study we used our recently published CREST protocol [Pracht et al., Phys. Chem. Chem. Phys., 2020, 22, 7169-7192] to generate conformer ensembles for a variety of 40 challenging transition metal containing molecules, which were then used to form a comprehensive conformational energy benchmark set termed TMCONF40. Several low-cost semiempirical, density functional theory (DFT) and force-field methods were compared to high level DLPNO-CCSD(T1) and double-hybrid DFT reference values. Close attention was paid to the energetic ordering of the conformers in the statistical evaluation. With respect to the double-hybrid references, both tested low-cost composite DFT methods produce high Pearson correlation coefficients of rp,mean,B97-3c//B97-3c = 0.922 and rp,mean,PBEh-3c//B97-3c = 0.890, with mean absolute deviations close to or below 1 kcal mol-1. This good performance also holds for a comparison to DLPNO-CCSD(T1) reference energies for a smaller subset termed TMCONF5. Based on DFT geometries, the GFNn-xTB methods yield reasonable Pearson correlation coefficients of rp,mean,GFN1-xTB//B97-3c = 0.617 (MADmean = 2.15 kcal mol-1) and rp,mean,GFN2-xTB//B97-3c = 0.567 (MADmean = 2.68 kcal mol-1), outperforming the widely used PMx methods on the TMCONF40 test set. Employing the low-cost composite DFT method B97-3c on GFN2-xTB geometries yields an slightly improved correlation of rp,mean,B97-3c//GFN2-xTB = 0.632. Furthermore, for 68% of the investigated complexes at least one low-energy conformer was found that is more stable than the respective crystal structure conformation, which signals the importance of conformational studies. General recommendations for the application of the CREST protocol and DFT methods for transition metal conformational energies are given.
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Affiliation(s)
- Markus Bursch
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstr. 4, 53115 Bonn, Germany.
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88
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Azizollahi H, García-López JA. Recent Advances on Synthetic Methodology Merging C-H Functionalization and C-C Cleavage. Molecules 2020; 25:E5900. [PMID: 33322116 PMCID: PMC7764206 DOI: 10.3390/molecules25245900] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 02/08/2023] Open
Abstract
The functionalization of C-H bonds has become a major thread of research in organic synthesis that can be assessed from different angles, for instance depending on the type of catalyst employed or the overall transformation that is carried out. This review compiles recent progress in synthetic methodology that merges the functionalization of C-H bonds along with the cleavage of C-C bonds, either in intra- or intermolecular fashion. The manuscript is organized in two main sections according to the type of substrate in which the cleavage of the C-C bond takes place, basically attending to the scission of strained or unstrained C-C bonds. Furthermore, the related research works have been grouped on the basis of the mechanistic aspects of the different transformations that are carried out, i.e.,: (a) classic transition metal catalysis where organometallic intermediates are involved; (b) processes occurring via radical intermediates generated through the use of radical initiators or photochemically; and (c) reactions that are catalyzed or mediated by suitable Lewis or Brønsted acid or bases, where molecular rearrangements take place. Thus, throughout the review a wide range of synthetic approaches show that the combination of C-H and C-C cleavage in single synthetic operations can serve as a platform to achieve complex molecular skeletons in a straightforward manner, among them interesting carbo- and heterocyclic scaffolds.
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Affiliation(s)
- Hamid Azizollahi
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
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89
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Murugesan K, Donabauer K, König B. Visible‐Light‐Promoted Metal‐Free Synthesis of (Hetero)Aromatic Nitriles from C(sp
3
)−H Bonds**. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
| | | | - Burkhard König
- Faculty of Chemistry and Pharmacy University of Regensburg Germany
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90
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Gao H, Lin S, Zhang S, Chen W, Liu X, Yang G, Lerner RA, Xu H, Zhou Z, Yi W. gem
‐Difluoromethylene Alkyne‐Enabled Diverse C−H Functionalization and Application to the on‐DNA Synthesis of Difluorinated Isocoumarins. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202013052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hui Gao
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Shuang Lin
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Shuning Zhang
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Weijie Chen
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Xiawen Liu
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Richard A. Lerner
- Department of Chemistry Scripps Research Institute La Jolla CA 92037 USA
| | - Hongtao Xu
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Zhi Zhou
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Wei Yi
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
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91
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Gao H, Lin S, Zhang S, Chen W, Liu X, Yang G, Lerner RA, Xu H, Zhou Z, Yi W. gem
‐Difluoromethylene Alkyne‐Enabled Diverse C−H Functionalization and Application to the on‐DNA Synthesis of Difluorinated Isocoumarins. Angew Chem Int Ed Engl 2020; 60:1959-1966. [DOI: 10.1002/anie.202013052] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Hui Gao
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Shuang Lin
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Shuning Zhang
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Weijie Chen
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Xiawen Liu
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Richard A. Lerner
- Department of Chemistry Scripps Research Institute La Jolla CA 92037 USA
| | - Hongtao Xu
- Shanghai Institute for Advanced Immunochemical Studies & School of Life Science and Technology ShanghaiTech University Shanghai 201210 P. R. China
| | - Zhi Zhou
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
| | - Wei Yi
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences & the Fifth Affiliated Hospital Guangzhou Medical University Guangzhou Guangdong 511436 P. R. China
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92
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Rosenthal U. Update for Reactions of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes: A Never-Ending Story? Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00622] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- U. Rosenthal
- Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Straße 29A, 18059 Rostock, Germany
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93
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Pearce AJ, Cheng Y, Dunscomb RJ, Tonks IA. Generation of Masked Ti II Intermediates from Ti IV Amides via β-H Abstraction or Alkyne Deprotonation: An Example of Ti-Catalyzed Nitrene-Coupled Transfer Hydrogenation. Organometallics 2020; 39:3771-3774. [PMID: 34321708 DOI: 10.1021/acs.organomet.0c00577] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Simple Ti amide complexes are shown to act as sources for masked TiII intermediates via several pathways, as demonstrated through the investigation of a unique Ti-catalyzed nitrene-coupled transfer hydrogenation of 3-hexyne. This reaction proceeds through reduction of azobenzene by a masked TiII catalyst, wherein both amines and 3-hexyne can serve as the hydrogen source/reductant for Ti by forming putative titanaziridines via β-H abstraction or putative titanacyclopentynes via protonolysis, respectively.
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Affiliation(s)
- Adam J Pearce
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Yukun Cheng
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Rachel J Dunscomb
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
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94
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Martínez AR, Morales LP, Ojeda ED, Rodríguez MC, Rodríguez-García I. The Proven Versatility of Cp 2TiCl. J Org Chem 2020; 86:1311-1329. [PMID: 33147037 DOI: 10.1021/acs.joc.0c01233] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the last two decades, titanocene monochloride has been postulated as a monoelectronic transfer reagent capable of catalyzing an important variety of chemical transformations. In this Perspective, our contributions to this growing field of research are summarized and analyzed. Especially known have been our contributions in C-C bond formation reactions, hydrogen-atom transfer from water to radicals, and isomerization reactions, as well as the development of a catalytic cycle that has subsequently allowed the preparation of a great variety of natural terpenes. It is also worth mentioning our contribution in the postulation of this single-electron transfer agent (SET) as a new green catalyst with a broad range of applications in organic and organometallic chemistry. The most significant catalytic processes developed by other research groups are also briefly described, with special emphasis on the reaction mechanisms involved. Finally, a reflection is made on the future trends in the research of this SET, aimed at consolidating this chemical as a new green reagent that will be widely used in fine chemistry, green chemistry, and industrial chemical processes.
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Affiliation(s)
- Antonio Rosales Martínez
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - Laura Pozo Morales
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - Emilio Díaz Ojeda
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
| | - María Castro Rodríguez
- Department of Chemical Engineering, Escuela Politécnica Superior, University of Sevilla, 41011 Sevilla, Spain
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95
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Yan M, Ma R, Chen R, Wang L, Wang Z, Ma Y. Synthesis of 1,2-dihydro-1,3,5-triazine derivatives via Cu(II)-catalyzed C(sp 3)-H activation of N, N-dimethylethanolamine with amidines. Chem Commun (Camb) 2020; 56:10946-10949. [PMID: 32940285 DOI: 10.1039/d0cc03820b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1,2-Dihydro-1,3,5-triazines and symmetrical 1,3,5-triazines were obtained in up to 81% yields from amidines and N,N-dimethylethanolamine catalyzed by CuCl2. The reaction involves three C-N bond formations during the oxidative annulation process and the mechanism was proposed. This efficient synthesis of 1,2-dihydro-1,3,5-triazines was developed for the first time.
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Affiliation(s)
- Min Yan
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China. and School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, 310053, P. R. China
| | - Renchao Ma
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China.
| | - Rener Chen
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China.
| | - Lei Wang
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China.
| | - Zhiming Wang
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China.
| | - Yongmin Ma
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, 1139 Shifu Avenue, Taizhou, 318000, P. R. China. and School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, 310053, P. R. China
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96
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Zhang J, Wang S, Zhang Y, Feng Z. Iron‐Catalyzed Cross‐Coupling Reactions for the Construction of Carbon‐Heteroatom Bonds. ASIAN J ORG CHEM 2020. [DOI: 10.1002/ajoc.202000334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Juan Zhang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research School of Pharmaceutical Sciences Chongqing University 55 Daxuecheng Road Chongqing 401331 China
| | - Siyu Wang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research School of Pharmaceutical Sciences Chongqing University 55 Daxuecheng Road Chongqing 401331 China
| | - Yun Zhang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research School of Pharmaceutical Sciences Chongqing University 55 Daxuecheng Road Chongqing 401331 China
| | - Zhang Feng
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research School of Pharmaceutical Sciences Chongqing University 55 Daxuecheng Road Chongqing 401331 China
- Sichuan Key Laboratory of Medical Imaging & Department of Chemistry School of Preclinical Medicine North Sichuan Medical College 234 Fujiang Road Nanchong Sichuan 637000 China
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97
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Ataee‐Kachouei T, Nasr‐Esfahani M, Mohammadpoor‐Baltork I, Mirkhani V, Moghadam M, Tangestaninejad S, Notash B. Ce(IV) immobilized on halloysite nanotube–functionalized dendrimer (Ce(IV)–G2): A novel and efficient dendritic catalyst for the synthesis of pyrido[3,2‐
c
]coumarin derivatives. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5948] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Tahereh Ataee‐Kachouei
- Department of Chemistry, Catalysis Division University of Isfahan Isfahan 81746‐73441 Iran
| | | | | | - Valiollah Mirkhani
- Department of Chemistry, Catalysis Division University of Isfahan Isfahan 81746‐73441 Iran
| | - Majid Moghadam
- Department of Chemistry, Catalysis Division University of Isfahan Isfahan 81746‐73441 Iran
| | | | - Behrouz Notash
- Department of Inorganic Chemistry and Catalysis Shahid Beheshti University General Campus, Evin Tehran 1983963113 Iran
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98
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In Vitro Corrosion of Titanium Nitride and Oxynitride-Based Biocompatible Coatings Deposited on Stainless Steel. COATINGS 2020. [DOI: 10.3390/coatings10080710] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The reactive cathodic arc deposition technique was used to produce Ti nitride and oxynitride coatings on 304 stainless steel substrates (SS). Both mono (SS/TiN, SS/TiNO) and bilayer coatings (SS/TiN/TiNO and SS/TiNO/TiN) were investigated in terms of elemental and phase composition, microstructure, grain size, morphology, and roughness. The corrosion behavior in a solution consisting of 0.10 M NaCl + 1.96 M H2O2 was evaluated, aiming for biomedical applications. The results showed that the coatings were compact, homogeneously deposited on the substrate, and displaying rough surfaces. The XRD analysis indicated that both mono and bilayer coatings showed only cubic phases with (111) and (222) preferred orientations. The highest crystallinity was shown by the SS/TiN coating, as indicated also by the largest grain size of 23.8 nm, which progressively decreased to 16.3 nm for the SS/TiNO monolayer. The oxynitride layers exhibited the best in vitro corrosion resistance either as a monolayer or as a top layer in the bilayer structure, making them a good candidate for implant applications.
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99
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Beaumier EP, Ott AA, Wen X, Davis-Gilbert ZW, Wheeler TA, Topczewski JJ, Goodpaster JD, Tonks IA. Ti-catalyzed ring-opening oxidative amination of methylenecyclopropanes with diazenes. Chem Sci 2020; 11:7204-7209. [PMID: 34123005 PMCID: PMC8159277 DOI: 10.1039/d0sc01998d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/20/2020] [Indexed: 12/22/2022] Open
Abstract
The ring-opening oxidative amination of methylenecyclopropanes (MCPs) with diazenes catalyzed by py3TiCl2(NR) complexes is reported. This reaction selectively generates branched α-methylene imines as opposed to linear α,β-unsaturated imines, which are difficult to access via other methods. Products can be isolated as the imine or hydrolyzed to the corresponding ketone in good yields. Mechanistic investigation via density functional theory suggests that the regioselectivity of these products results from a Curtin-Hammett kinetic scenario, where reversible β-carbon elimination of a spirocyclic [2 + 2] azatitanacyclobutene intermediate is followed by selectivity-determining β-hydrogen elimination of the resulting metallacycle. Further functionalizations of these branched α-methylene imine products are explored, demonstrating their utility as building blocks.
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Affiliation(s)
- Evan P Beaumier
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Amy A Ott
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Xuelan Wen
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Zachary W Davis-Gilbert
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - T Alexander Wheeler
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Joseph J Topczewski
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Jason D Goodpaster
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
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100
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Moore JT, Lu CC. Catalytic Hydrogenolysis of Aryl C–F Bonds Using a Bimetallic Rhodium–Indium Complex. J Am Chem Soc 2020; 142:11641-11646. [DOI: 10.1021/jacs.0c04937] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- James T. Moore
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Connie C. Lu
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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