1
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Wang J, Lin Phang Y, Yu YJ, Liu NN, Xie Q, Zhang FL, Jin JK, Wang YF. Boryl Radical as a Catalyst in Enabling Intra- and Intermolecular Cascade Radical Cyclization Reactions: Construction of Polycyclic Molecules. Angew Chem Int Ed Engl 2024; 63:e202405863. [PMID: 38589298 DOI: 10.1002/anie.202405863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/10/2024]
Abstract
Cascade radical cyclization constitutes an atom- and step-economic route for rapid assembly of polycyclic molecular skeletons. Although an array of redox-active metal catalysts has recently shown robust applications in enabling various catalytic cascade radical processes, the use of free organic radical as the catalyst, which is capable of triggering strategically distinct cascades, has rarely been developed. Here, we disclosed that the benzimidazolium-based N-heterocyclic carbene (NHC)-boryl radical is capable of catalyzing cascade cyclization reactions in both intra- and intermolecular pathways, assembling [5,5] fused bicyclic and [6,6,6] fused tricyclic molecules, respectively. The catalytic reactions start with the chemo- and regioselective addition of the boryl radical catalyst to a tethered alkene or alkyne moiety, followed by either an intramolecular formal [3+2] or an intermolecular [2+2+2] cycloaddition process to construct bicyclo[3.3.0]octane or tetrahydrophenanthridine skeletons, respectively. Eventually, a β-elimination occurs to release the boryl radical catalyst, completing a catalytic cycle. High to excellent diastereoselectivity is achieved in both catalytic reactions under substrate control.
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Affiliation(s)
- Jie Wang
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yee Lin Phang
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - You-Jie Yu
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Nan-Nan Liu
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Qiang Xie
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Feng-Lian Zhang
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Ji-Kang Jin
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yi-Feng Wang
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, the, First Affiliated Hospital of USTC, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
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2
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Wang B, Huang X, Bi H, Liu J. Electroreductive alkylations of (hetero)arenes with carboxylic acids. Nat Commun 2024; 15:4970. [PMID: 38862567 PMCID: PMC11166922 DOI: 10.1038/s41467-024-49355-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 06/03/2024] [Indexed: 06/13/2024] Open
Abstract
Carboxylic acids are widely available and generally inexpensive from abundant biomass feedstocks, and they are suitable and generic coupling partners in synthetic chemistry. Reported herein is an electroreductive coupling of stable and versatile carboxylic acids with (hetero)arenes using protons as the hydrogen source. The application of an earth-abundant titanium catalyst has significantly improved the deoxygenative reduction process. Preliminary mechanistic studies provide insights into the deoxygenative reduction of in-situ generated ketone pathway, and the intermediacy generation of ketyl radical and alkylidene titanocene. Without the necessity of pressurized hydrogen or stoichiometric hydride as reductants, this protocol enables highly selective and straightforward synthesis of various functionalized and structurally diverse alkylbenzenes under mild conditions. The utility of this reaction is further demonstrated through practical and valuable isotope incorporation from readily available deuterium source.
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Affiliation(s)
- Bing Wang
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Xianshuai Huang
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Huihua Bi
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China
| | - Jie Liu
- College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, China.
- Greater Bay Area Institute for Innovation, Hunan University, 511300, Guangzhou, China.
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3
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Chen ZH, Zheng YQ, Huang HG, Wang KH, Gong JL, Liu WB. From Quaternary Carbon to Tertiary C(sp 3)-Si and C(sp 3)-Ge Bonds: Decyanative Coupling of Malononitriles with Chlorosilanes and Chlorogermanes Enabled by Ni/Ti Dual Catalysis. J Am Chem Soc 2024; 146:14445-14452. [PMID: 38739877 DOI: 10.1021/jacs.4c04495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Transition-metal-catalyzed C-Si/Ge cross-coupling offers promising avenues for the synthesis of organosilanes/organogermanes, yet it is fraught with long-standing challenges. A Ni/Ti-catalyzed strategy is reported here, allowing the use of disubstituted malononitriles as tertiary C(sp3) coupling partners to couple with chlorosilanes and chlorogermanes, respectively. This method enables the catalytic cleavage of the C(sp3)-CN bond of the quaternary carbon followed by the formation of C(sp3)-Si/C(sp3)-Ge bonds from ubiquitously available starting materials. The efficiency and generality are showcased by a broad scope for both of the coupling partners, therefore holding the potential to synthesize structurally diverse quaternary organosilanes and organogermanes that were difficult to access previously.
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Affiliation(s)
- Zi-Hao Chen
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yu-Qing Zheng
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Hong-Gui Huang
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Ke-Hao Wang
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jun-Lin Gong
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Bo Liu
- Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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4
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Li L, Yang S, Xu Z, Li S, Jiang J, Zhang YQ. Dinuclear Titanium(III)-Catalyzed Radical-Type Kinetic Resolution of Epoxides for the Enantioselective Synthesis of cis-Glycidic Esters. J Am Chem Soc 2024; 146:13546-13557. [PMID: 38690842 DOI: 10.1021/jacs.4c03346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Glycidic esters represent pivotal constituents in synthetic chemistry, offering enhanced versatility for tailoring toward a diverse array of molecular targets in comparison with simple epoxides. While considerable progress has been made in the asymmetric synthesis of trans- and trisubstituted glycidic esters, achieving enantioselective preparation of cis-glycidic esters has remained a long-standing challenge. Here, we demonstrate a selectivity-predictable modular platform for the asymmetric synthesis of cis-glycidic esters via a novel dinuclear (salen)titanium(III)-catalyzed radical-type kinetic resolution (KR) approach. This radical KR protocol operates under mild conditions and demonstrates a wide substrate scope, facilitating the synthesis of alkyl- and aryl-substituted cis-glycidic esters with high levels of regioselectivity and enantioselectivity, along with hydroxy ester byproducts representing synthetically valuable motifs as well. This study presents a unique exploration of radical-type KR applied to epoxides, effectively overcoming the steric challenges inherent in conventional nucleophilic-type methodologies typically employed in epoxide chemistry.
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Affiliation(s)
- Longfei Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shuo Yang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Zhongyun Xu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shengxiao Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Jie Jiang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Yong-Qiang Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
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5
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Morozov AG, Dodonov VA, Rychagova EA, Ketkov SY, Fedushkin IL. Ligand-Induced Intramolecular Redox Diversity in Titanium Complexes with Acenaphthene-1,2-diimine. Inorg Chem 2024; 63:4657-4668. [PMID: 38401059 DOI: 10.1021/acs.inorgchem.3c04250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
A series of the chlorido and alkoxychlorido titanium complexes of the general formula (dpp-Bian)Ti(OiPr)nCl3-n, where dpp-Bian = 1,2-bis[(2,6-iPr2C6H3)imino]acenaphthene n = 0 (2), 1 (3), 2 (4), as well as (dpp-Bian)Ti(OiPr)2 (5) and (dpp-Bian)Ti(OiPr)Cl3 (3-Cl), were isolated and characterized using single-crystal X-ray diffraction analysis and spectroscopic studies combined with density functional theory (DFT) calculations. In the solid state, compounds 2-4 reveal a square-pyramidal geometry at the metal center supported with monoanionic dpp-Bian, whereas 3-Cl with a neutral diimine ligand and 5 bearing a dianionic enebisamide dpp-Bian show, respectively, an octahedral and tetrahedral coordination surrounding the metal ion. Paramagnetic complexes 2-4 exhibit electron paramagnetic resonance spectra in both toluene solution and solid state, confirming the transfer of spin density from the metal ion to the dpp-Bian ligand as the number of alkoxy groups increases. The increase in polarity of the Ti-N bonds in the row 2 < 3 < 4 contributes to enhanced stability of the metal complexes with respect to O-donor molecules. Thus, in tetrahydrofuran (THF), compounds 2 and 3 undergo reversible solvolysis, whereas complex 4 is stable. The charge and spin density distributions as well as molecular orbital energies in 2-4 were analyzed on the basis of DFT calculations which also provided information on the electronic transition energies, absorption band assignments, and thermodynamic parameters of the reactions between the complexes and THF.
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Affiliation(s)
- Alexander G Morozov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Vladimir A Dodonov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Elena A Rychagova
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Sergey Yu Ketkov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Igor L Fedushkin
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
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6
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Yao L, Bao J, Wang Y, Gui J. Titanium-Mediated Dehydroxylative Cross-Coupling of Allylic Alcohols with Electron-Deficient Olefins. Org Lett 2024; 26:1243-1248. [PMID: 38315609 DOI: 10.1021/acs.orglett.4c00061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Herein we report a Ti(III)-mediated dehydroxylative cross-coupling reaction of allylic alcohols with electron-deficient olefins. This reaction is amenable to various synthetically versatile allylic alcohols, including geraniol and farnesol, providing a general method for dehydroxylative C-C bond formation. We demonstrated the reaction's utility by simplifying the syntheses of eight useful building blocks that are otherwise laborious to prepare.
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Affiliation(s)
- Liangcai Yao
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Jiajing Bao
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Yun Wang
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Jinghan Gui
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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7
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Mikhaliov A, Flerko A, Atroshchanka D, Harakhouski A, Budko A, Stasko K, Bialkevich A, Shepialevich S, Rusakovich Y, Hurski A. Visible-Light-Promoted Reduction of Epoxides, Hydroxysulfonates, and Halohydrines with Alkyltitanium Alkoxides. Org Lett 2024; 26:178-182. [PMID: 38148254 DOI: 10.1021/acs.orglett.3c03802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Alkyltitanium alkoxides generally serve as nucleophiles in reactions with carbonyl compounds and cross-coupling. Their application as reductants is known but remains underdeveloped. Here, we report that irradiation with visible light makes these organometallic compounds efficient reducing agents for the dehalogenation of 1,2- and 1,3-haloalcohols. This reaction was utilized for the reduction of epoxides and sulfonates, which proceeded through a sequence of the in situ halohydrin formation and photochemical dehalogenation. Ester, amide, nitrile, alkyne, and remote bromide groups were stable under the reaction conditions.
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Affiliation(s)
- Artyom Mikhaliov
- Republican Scientific Center of Human Issues, Belarusian State University, Kurčatava 7, Minsk 220064, Belarus
| | - Aliaksei Flerko
- Department of Chemistry, Belarusian State University Niezaliežnasci 4, Minsk 220030, Belarus
| | - Dziyana Atroshchanka
- Republican Scientific Center of Human Issues, Belarusian State University, Kurčatava 7, Minsk 220064, Belarus
| | - Aliaksei Harakhouski
- Republican Scientific Center of Human Issues, Belarusian State University, Kurčatava 7, Minsk 220064, Belarus
| | - Arsenii Budko
- Department of Chemistry, Belarusian State University Niezaliežnasci 4, Minsk 220030, Belarus
| | - Kirill Stasko
- Department of Chemistry, Belarusian State University Niezaliežnasci 4, Minsk 220030, Belarus
| | - Andrei Bialkevich
- Department of Chemistry, Belarusian State University Niezaliežnasci 4, Minsk 220030, Belarus
| | - Siarhei Shepialevich
- Department of Chemistry, Belarusian State University Niezaliežnasci 4, Minsk 220030, Belarus
| | - Yahor Rusakovich
- Republican Scientific Center of Human Issues, Belarusian State University, Kurčatava 7, Minsk 220064, Belarus
| | - Alaksiej Hurski
- Republican Scientific Center of Human Issues, Belarusian State University, Kurčatava 7, Minsk 220064, Belarus
- Scientific Testing Center Campilab Ltd., Centraĺnaja 30A, Dynaraŭka 222202, Belarus
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8
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Zhang Z, Slak D, Krebs T, Leuschner M, Schmickler N, Kuchuk E, Schmidt J, Domenianni LI, Kleine Büning JB, Grimme S, Vöhringer P, Gansäuer A. A Chiral Titanocene Complex as Regiodivergent Photoredox Catalyst: Synthetic Scope and Mechanism of Catalyst Generation. J Am Chem Soc 2023. [PMID: 38016173 DOI: 10.1021/jacs.3c08029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
We describe a combined synthetic, spectroscopic, and computational study of a chiral titanocene complex as a regiodivergent photoredox catalyst (PRC). With Kagan's complex catCl2 either monoprotected 1,3-diols or 1,4-diols can be obtained in high selectivity from a common epoxide substrate in a regiodivergent epoxide opening depending on which enantiomer of the catalyst is employed. Due to the catalyst-controlled regioselectivity of ring opening and the broader substrate scope, the PRC with catCl2 is also a highly attractive branching point for diversity-oriented synthesis. The photochemical processes of cat(NCS)2, a suitable model for catCl2, were probed by time-correlated single-photon counting. The photoexcited complex displays a thermally activated delayed fluorescence as a result of a singlet-triplet equilibration, S1 ⇄ T1, via intersystem crossing and recrossing. Its triplet state is quenched by electron transfer to the T1 state. Computational and cyclic voltammetry studies highlight the importance of our sulfonamide additive. By bonding to sulfonamide additives, chloride abstraction from [catCl2]- is facilitated, and catalyst deactivation by coordination of the sulfonamide group is circumvented.
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Affiliation(s)
- Zhenhua Zhang
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Daniel Slak
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Tim Krebs
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Marcel Leuschner
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Niklas Schmickler
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Ekaterina Kuchuk
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Jonas Schmidt
- Clausius Institute for Physical and Theoretical Chemistry, Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
| | - Luis Ignacio Domenianni
- Clausius Institute for Physical and Theoretical Chemistry, Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
| | - Julius B Kleine Büning
- Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Peter Vöhringer
- Clausius Institute for Physical and Theoretical Chemistry, Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
| | - Andreas Gansäuer
- Kekulé Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
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9
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Wen L, Ding J, Duan L, Wang S, An Q, Wang H, Zuo Z. Multiplicative enhancement of stereoenrichment by a single catalyst for deracemization of alcohols. Science 2023; 382:458-464. [PMID: 37883537 DOI: 10.1126/science.adj0040] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 09/04/2023] [Indexed: 10/28/2023]
Abstract
Stereochemical enrichment of a racemic mixture by deracemization must overcome unfavorable entropic effects as well as the principle of microscopic reversibility; recently, photochemical reaction pathways unveiled by the energetic input of light have led to innovations toward this end, most often by ablation of a stereogenic C(sp3)-H bond. We report a photochemically driven deracemization protocol in which a single chiral catalyst effects two mechanistically different steps, C-C bond cleavage and C-C bond formation, to achieve multiplicative enhancement of stereoinduction, which leads to high levels of stereoselectivity. Ligand-to-metal charge transfer excitation of a titanium catalyst coordinated by a chiral phosphoric acid or bisoxazoline efficiently enriches racemic alcohols that feature adjacent and fully substituted stereogenic centers to enantiomeric ratios up to 99:1. Mechanistic investigations support a pathway of sequential radical-mediated bond scission and bond formation through a common prochiral intermediate and reveal that, although the overall stereoenrichment is high, the selectivity in each individual step is moderate.
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Affiliation(s)
- Lu Wen
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jia Ding
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Lingfei Duan
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shun Wang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Qing An
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Hexiang Wang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhiwei Zuo
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
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10
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Li J, Cao C, Wu H, Dong K. Nickel/Titanocene-Catalyzed Electrophilic Acylation Coupling of Styrene Oxides. Org Lett 2023; 25:6959-6963. [PMID: 37726896 DOI: 10.1021/acs.orglett.3c02402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
The cross-coupling of epoxides with acyl chlorides or anhydrides by a nickel/titanocene dual catalytic system is established. A variety of synthetically useful β-hydroxy ketones were obtained in good to high yields by using modified pyridine-oxazoline ligand. The reaction proceeds via the cooperation of titanocene-catalyzed ring-opening of epoxides and nickel-catalyzed acylation of the benzylic radical intermediate.
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Affiliation(s)
- Jincan Li
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P. R. China
| | - Chang Cao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P. R. China
| | - Haihong Wu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P. R. China
| | - Kaiwu Dong
- Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P. R. China
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11
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Shen J, Xu Z, Yang S, Li S, Jiang J, Zhang YQ. Quaternary Stereocenters via Catalytic Enantioconvergent Allylation of Epoxides. J Am Chem Soc 2023; 145:21122-21131. [PMID: 37722078 DOI: 10.1021/jacs.3c08188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
The development of catalytic and enantioselective transformations for the synthesis of all-carbon quaternary stereocenters has long been recognized as a significant challenge in organic synthesis. While considerable progress has been made in asymmetric allylations, their potential to functionalize the commonly used synthon, epoxide, remains largely underexplored. Here we demonstrate the first highly regio- and enantioselective allylation of epoxides that delivers a range of quaternary stereocenters in the face of potentially problematic elimination and protonation reactions. The reaction proceeds via a radical approach under mild conditions and benefits from the use of earth-abundant titanium with a highly sophisticated salen ligand, which facilitates remarkable enantiocontrol and suppresses undesired side reactions. The resulting allylation products are multifunctional building blocks that can be elaborated chemo- and stereoselectively to a broad array of stereodefined structural motifs.
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Affiliation(s)
- Jian Shen
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Zhongyun Xu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shuo Yang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Shengxiao Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Jie Jiang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Yong-Qiang Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
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Jiang Y, Zhang Y, Lee BC, Koh MJ. Diversification of Glycosyl Compounds via Glycosyl Radicals. Angew Chem Int Ed Engl 2023; 62:e202305138. [PMID: 37278303 DOI: 10.1002/anie.202305138] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/07/2023]
Abstract
Glycosyl radical functionalization is one of the central topics in synthetic carbohydrate chemistry. Recent advances in metal-catalyzed cross-coupling chemistry and metallaphotoredox catalysis provided powerful platforms for glycosyl radical diversification. In particular, the discovery of new glycosyl radical precursors in conjunction with these advanced reaction technologies have significantly expanded the space for glycosyl compound synthesis. In this Review, we highlight the most recent progress in this area starting from 2021, and the reports included will be categorized based on different reaction types for better clarity.
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Affiliation(s)
- Yi Jiang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Yijun Zhang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
- Department of Chemistry, Southern University of Science and Technology, 1088 Xueyuan Road, Shenzhen, 518055, China
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
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Schmidt J, Domenianni LI, Leuschner M, Gansäuer A, Vöhringer P. Observing the Entry Events of a Titanium-Based Photoredox Catalytic Cycle in Real Time. Angew Chem Int Ed Engl 2023; 62:e202307178. [PMID: 37335756 DOI: 10.1002/anie.202307178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/19/2023] [Accepted: 06/19/2023] [Indexed: 06/21/2023]
Abstract
Titanium-based catalysis in single electron transfer (SET) steps has evolved into a versatile approach for the synthesis of fine chemicals and first attempts have recently been made to enhance its sustainability by merging it with photo-redox (PR) catalysis. Here, we explore the photochemical principles of all-Ti-based SET-PR-catalysis, i.e. in the absence of a precious metal PR-co-catalyst. By combining time-resolved emission with ultraviolet-pump/mid-infrared-probe (UV/MIR) spectroscopy on femtosecond-to-microsecond time scales we quantify the dynamics of the critical events of entry into the catalytic cycle; namely, the singlet-triplet interconversion of the do-it-all titanocene(IV) PR-catalyst and its one-electron reduction by a sacrificial amine electron donor. The results highlight the importance of the PR-catalyst's singlet-triplet gap as a design guide for future improvements.
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Affiliation(s)
- Jonas Schmidt
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
| | - Luis I Domenianni
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
| | - Marcel Leuschner
- Kekulé Institute for Organic Chemistry and Biochemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé Institute for Organic Chemistry and Biochemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Peter Vöhringer
- Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115, Bonn, Germany
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Yu P, Zhang W, Lin S. Enantioselective radical cascade cyclization via Ti-catalyzed redox relay. Tetrahedron Lett 2023; 125:154617. [PMID: 37449084 PMCID: PMC10338015 DOI: 10.1016/j.tetlet.2023.154617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Radical cascade cyclization reactions provide an efficient method for the construction of polycyclic architectures with multiple stereogenic centers. However, achieving enantioselectivity control of this type of reaction is a challenging task. Here, we report an enantioselective cyclization of polyfunctional aryl cyclopropyl ketone and alkyne units, wherein the stereochemical outcome is directed by a chiral Ti(salen) catalyst. This transformation was proposed to proceed via a radical cascade process involving the reductive ring-opening of the cyclopropyl ketone followed by two annulation events entailing cyclization of the ensuing alkyl radical onto the alkyne and subsequent addition of the incipient vinyl radical to the Ti(IV)-enolate.
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Affiliation(s)
- Peng Yu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Wen Zhang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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Calvo-Molina A, del Horno E, Jover J, Pérez-Redondo A, Yélamos C, Zapata R. Monocyclopentadienyltitanium(III) Complexes with Hydridoborato Ligands. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- Adrián Calvo-Molina
- 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
| | - 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
| | - 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
| | - Rosa Zapata
- 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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Gavin JT, Belli RG, Roberts CC. Radical-Polar Crossover Catalysis with a d 0 Metal Enabled by a Redox-Active Ligand. J Am Chem Soc 2022; 144:21431-21436. [DOI: 10.1021/jacs.2c09114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Joshua T. Gavin
- Department of Chemistry, University of Minnesota─Twin Cities, 207 Pleasant St SE, Minneapolis, Minnesota 55455, United States
| | - Roman G. Belli
- Department of Chemistry, University of Minnesota─Twin Cities, 207 Pleasant St SE, Minneapolis, Minnesota 55455, United States
| | - Courtney C. Roberts
- Department of Chemistry, University of Minnesota─Twin Cities, 207 Pleasant St SE, Minneapolis, Minnesota 55455, United States
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Lin Q, Tong W, Shu XZ, Chen Y. Ti-Catalyzed Dehydroxylation of Tertiary Alcohols. Org Lett 2022; 24:8459-8464. [DOI: 10.1021/acs.orglett.2c03119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Quan Lin
- School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
- Center for Supramolecular Chemistry and Catalysis and Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
| | - Weiqi Tong
- Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
| | - Xing-Zhong Shu
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, People’s Republic of China
| | - Yunrong Chen
- Center for Supramolecular Chemistry and Catalysis and Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, People’s Republic of China
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Waste Biomass Selective and Sustainable Photooxidation to High-Added-Value Products: A Review. Catalysts 2022. [DOI: 10.3390/catal12101091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Researchers worldwide seek to develop convenient, green, and ecological production processes to synthesize chemical products with high added value. In this sense, lignocellulosic biomass photocatalysis is an excellent process for obtaining various outcomes for the industry. One issue of biomass transformation via heterogeneous catalysis into valuable chemicals is the selection of an adequate catalyst that ensures high conversion and selectivity at low costs. Titanium oxide (TiO2), is widely used for several applications, including photocatalytic biomass degradation, depolymerization, and transformation. Graphite carbon nitride (g-C3N4) is a metal-free polymeric semiconductor with high oxidation and temperature resistance and there is a recent interest in developing this catalyst. Both catalysts are amenable to industrial production, relatively easy to dope, and suited for solar light absorption. Recent investigations also show the advantages of using heterojunctions, for biomass derivates production, due to their better solar spectrum absorption properties and, thus, higher efficiency, conversion, and selectivity over a broader spectrum. This work summarizes recent studies that maximize selectivity and conversion of biomass using photocatalysts based on TiO2 and g-C3N4 as supports, as well as the advantages of using metals, heterojunctions, and macromolecules in converting cellulose and lignin. The results presented show that heterogeneous photocatalysis is an interesting technology for obtaining several chemicals of industrial use, especially when using TiO2 and g-C3N4 doped with metals, heterojunctions, and macromolecules because these modified catalysts permit higher conversion and selectivity, milder reaction conditions, and reduced cost due to solar light utilization. In order to apply these technologies, it is essential to adopt government policies that promote the use of photocatalysts in the industry, in addition to encouraging active collaboration between photooxidation research groups and companies that process lignocellulosic biomass.
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