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Visible light mediated iron-catalyzed addition of oxamic acids to imines. RSC Adv 2024; 14:12528-12532. [PMID: 38638815 PMCID: PMC11024671 DOI: 10.1039/d4ra02258k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 04/09/2024] [Indexed: 04/20/2024] Open
Abstract
Oxamic acids where shown to add to imines, providing a broad range of α-aminoacid amides in generally good yields. The process is efficient on pre-formed imines but may also be conducted using a 3-component strategy by simply mixing aldehydes, amines and oxamic acids in the presence of ferrocene, acting both as a photocatalyst under visible light and as a Lewis acid. The reaction proceeds through the addition onto the imine of a carbamoyl radical intermediate generated through a charge transfer from the carboxylate ligand to a Fe(iii) species (LMCT).
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2
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Dual photoredox nickel-catalyzed silylation of aryl/heteroaryl bromides using hydrosilanes. Chem Commun (Camb) 2023; 59:11369-11372. [PMID: 37665260 DOI: 10.1039/d3cc03246a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Dual Ni and Ir catalysis enables the preparation of arylsilanes having a (TMS)3Si substituent from the corresponding aryl bromides and (TMS)3SiH at 30 °C using visible-light irradiation. This protocol avoids strong bases, high temperature and air and moisture sensitive silyl reagents, providing the expected arylsilanes in moderate to good yields. The reaction was shown to proceed through a silyl radical, likely generated by hydrogen atom abstraction from (TMS)3SiH by a bromide radical.
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Thiochromane Formation via Visible-Light-Mediated Intramolecular δ-C(sp 3)-H Bond Arylation of Sulfonamides. Org Lett 2023; 25:3072-3077. [PMID: 37092716 DOI: 10.1021/acs.orglett.3c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Visible-light-mediated intramolecular site-selective δ-C(sp3)-H bond arylation of aliphatic trifluoromethanesulfonamides was developed. The reaction proceeds through a radical cascade, including the generation of a sulfonamidyl radical, which triggers a 1,5-hydrogen atom transfer, affording a δ-C-centered radical, which finally cyclized onto a neighboring thiopolyfluoroaryl moiety to deliver a range of synthetically useful thiochromanes. The cyclization process occurs through two distinct pathways depending upon the nature of the substituent X ortho to the native C-S bond.
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PIDA-mediated Oxidative Decarboxylation of Oxamic Acids. The Role of Radical Acidity Enhancement. Chemistry 2023; 29:e202202963. [PMID: 36583591 DOI: 10.1002/chem.202202963] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/28/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
The PIDA-mediated oxidative decarboxylation of oxamic acids in the presence of alcohols is shown to afford the corresponding urethanes under thermal conditions. Computational and experimental mechanistic exploration allows to rationalize the different reactivity of PIDA as compared to related cyclic BI-OAc and highlights the importance of the enhanced acidity of the proton in the carbamoyl radical intermediate.
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Correction: Oxamic acids: useful precursors of carbamoyl radicals. Chem Commun (Camb) 2022; 58:8452. [PMID: 35838002 DOI: 10.1039/d2cc90251f] [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
Correction for 'Oxamic acids: useful precursors of carbamoyl radicals' by Ikechukwu Martin Ogbu et al., Chem. Commun., 2022, 58, 7593-7607, https://doi.org/10.1039/D2CC01953A.
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Photocatalyzed decarboxylation of oxamic acids under near-infrared conditions. Chem Commun (Camb) 2022; 58:8802-8805. [PMID: 35838178 DOI: 10.1039/d2cc03155h] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photocatalyzed oxidative decarboxylation of oxamic acids under near-infrared irradiation using Os(bptpy)2(PF6)2 as catalyst is reported. The reaction was applied to the synthesis of urethanes and heterocyclic amides. Mechanistic studies and comparative penetration depths between the NIR and the visible light mediated processes are discussed.
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Abstract
This review article describes the recent development in the chemistry of carbamoyl radicals generated from oxamic acids. This mild and efficient method compares well with previous methods of generation of these nucleophilic radicals. The oxidative decarboxylation of oxamic acids can be mediated through thermal, photochemical, electrochemical or photoelectrochemical means, generating carbamoyl radicals, which may further add to unsaturated systems to provide a broad range of important amides. Oxidative decarboxylation of oxamic acids also offers a straightforward entry for the preparation of urethanes, ureas, and thioureas.
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Enantioselective Total Synthesis of (+)‐Eucophylline. Chemistry 2022; 28:e202200088. [DOI: 10.1002/chem.202200088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Indexed: 11/08/2022]
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Abstract
The structure determination of a series of biphenylsilyloxonium cations through NMR and XRD studies, supported by DFT calculations was carried out, allowing to get insights into the origin of the oxygen pyramidalization in biphenyl and binaphthylsilyl oxoniums. Low barrier of inversion in the oxygenyl series points toward a key role of the biaryl axis in the inversion of configuration at the oxygen center.
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Chiral Chalcogenyl-Substituted Naphthyl- and Acenaphthyl-Silanes and Their Cations. Chemistry 2020; 26:16441-16449. [PMID: 32627900 PMCID: PMC7756486 DOI: 10.1002/chem.202002977] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/02/2020] [Indexed: 11/30/2022]
Abstract
Cyclic silylated chalconium borates 13[B(C6F5)4] and 14[B(C6F5)4] with peri‐acenaphthyl and peri‐naphthyl skeletons were synthesized from unsymmetrically substituted silanes 3, 4, 6, 7, 9 and 10 using the standard Corey protocol (Chalcogen Ch=O, S, Se, Te). The configuration at the chalcogen atom is trigonal pyramidal for Ch=S, Se, Te, leading to the formation of cis‐ and trans‐isomers in the case of phenylmethylsilyl cations. With the bulkier tert‐butyl group at silicon, the configuration at the chalcogen atoms is predetermined to give almost exclusively the trans‐configurated cyclic silylchalconium ions. The barriers for the inversion of the configuration at the sulfur atoms of sulfonium ions 13 c and 14 a are substantial (72–74 kJ mol−1) as shown by variable temperature NMR spectroscopy. The neighboring group effect of the thiophenyl substituent is sufficiently strong to preserve chiral information at the silicon atom at low temperatures.
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Identification and analysis of new α- and β-hydroxy ketones related to the formation of 3-methyl-2,4-nonanedione in musts and red wines. Food Chem 2020; 305:125486. [DOI: 10.1016/j.foodchem.2019.125486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 11/29/2022]
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14
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Copper-catalyzed oxidative benzylic C(sp3)–H amination: direct synthesis of benzylic carbamates. Chem Commun (Camb) 2020; 56:13013-13016. [DOI: 10.1039/d0cc05226d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Cu(i)–diimine ligand combined with a N–F source allows the C–H abstraction and incorporation of a carbamate functional group in the hydrocarbons at the benzylic position.
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Urethanes synthesis from oxamic acids under electrochemical conditions. Chem Commun (Camb) 2020; 56:12226-12229. [DOI: 10.1039/d0cc05069e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Electrochemical decarboxylation of oxamic acids in the presence of alcohols provides urethanes.
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p-Anisaldehyde-Photosensitized Sulfonylcyanation of Chiral Cyclobutenes: Enantioselective Access to Cyclic and Acyclic Systems Bearing All-Carbon Quaternary Stereocenters. Org Lett 2019; 22:575-579. [DOI: 10.1021/acs.orglett.9b04345] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers. Beilstein J Org Chem 2019; 15:1822-1828. [PMID: 31467602 PMCID: PMC6693370 DOI: 10.3762/bjoc.15.176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 07/16/2019] [Indexed: 11/23/2022] Open
Abstract
Four-component coupling reactions between xanthogenates, alkenes, CO, and sulfonyl oxime ethers were studied. In the presence of hexabutylditin, working as a propagating radical reagent, the chain reaction proceeds, as expected, taking into account reagents polarities, affording the corresponding functionalized α-keto oximes. Although yields are modest, this rare one-pot four-component process is easy to carry out and the resulting compounds, bearing multiple functionalities, have the potential for further elaboration.
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An Approach towards the Synthesis of the Spiroimine Fragment of 13-Desmethylspirolide C and Gymnodimine A. Chemistry 2019; 25:1553-1560. [DOI: 10.1002/chem.201804972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 11/09/2022]
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21
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Abstract
Decarboxylative carbamoylation of heteroarenes using oxamic acids under visible-light irradiation is described.
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22
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Dehydrogenative Silylation of Alcohols Under Pd‐Nanoparticle Catalysis. Chemistry 2018; 25:728-732. [DOI: 10.1002/chem.201803989] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Indexed: 11/10/2022]
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Visible-light photocatalyzed oxidative decarboxylation of oxamic acids: a green route to urethanes and ureas. Chem Commun (Camb) 2018; 54:9337-9340. [PMID: 30073222 DOI: 10.1039/c8cc05462b] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A sustainable metal-free route to urethanes and ureas based on a photocatalyzed oxidative decarboxylation of oxamic acids is described. The reaction includes in situ generation of an isocyanate from the oxamic acid, using an organic dye as a photocatalyst, a hypervalent iodine reagent as an oxidant and a light source, which trigger the free-radical decarboxylation. This protocol successfully avoids the isolation, purification and storage of carcinogenic isocyanates and allows elaboration of urethanes and ureas in a one-pot process from commercially available sources.
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25
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26
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Poly(arylene vinylene) Synthesis via a Precursor Step-Growth Polymerization Route Involving the Ramberg–Bäcklund Reaction as a Key Post-Chemical Modification Step. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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28
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Oxidation of 1-Arylcyclohexa-2,5-dienes and Subsequent Double Michael Addition. A Rapid Access to the Büchi Ketone and the Pentacyclic Core of Aspidosperma Alkaloids. HETEROCYCLES 2018. [DOI: 10.3987/com-18-s(t)36] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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29
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A Unified Strategy Toward 5-, 6-, and 7-Membered Nitrogen Heterocycles Through Free Radical then Metal-Mediated Functionalization of Ene-carbamates. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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30
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31
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Acyl Radical Addition onto Aza-Baylis-Hillman Adducts: A Stereocontrolled Access to 2,3,5-Trisubstituted Pyrrolidines. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700362] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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32
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33
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Acyl Radical Addition to Activated Olefins: A Stereocontrolled Route to Polysubstituted Tetrahydrofurans and Lactones, and Application to the Total Synthesis of (+)-No. 2106 A. European J Org Chem 2017. [DOI: 10.1002/ejoc.201601624] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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34
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Organic Lewis Pairs Based on Phosphine and Electrophilic Silane for the Direct and Controlled Polymerization of Methyl Methacrylate: Experimental and Theoretical Investigations. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02205] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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35
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Free-Radical Carbo-Alkenylation of Olefins: Scope, Limitations and Mechanistic Insights. Chemistry 2017; 23:2439-2447. [DOI: 10.1002/chem.201605043] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Indexed: 02/04/2023]
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36
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Free-Radical Carbocyanation of Cyclopropenes: Stereocontrolled Access to All-Carbon Quaternary Stereocenters in Acyclic Systems. Org Lett 2016; 18:6156-6159. [DOI: 10.1021/acs.orglett.6b03163] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Stereocontrolled (Me3Si)3SiH-Mediated Radical and Ionic Hydride Transfer in Synthesis of 2,3,5-Trisubstituted THF. Org Lett 2016; 18:1542-5. [PMID: 26974171 DOI: 10.1021/acs.orglett.6b00303] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
2,3,5-Trisubstituted tetrahydrofurans were prepared stereoselectively through a two-step process involving the addition of an acyl radical to a β-silyloxy acrylic ester followed by an acid-catalyzed desilylation-ketalization sequence and a final oxocarbenium reduction step. High levels of 1,2- and 1,3-stereocontrol were attained when (Me3Si)3SiH was used as a radical followed by a ionic hydrogen transfer agent.
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38
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Free-radical Carbo-functionalization of Olefins Using Sulfonyl Derivatives. Chimia (Aarau) 2016; 70:34-42. [DOI: 10.2533/chimia.2016.34] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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39
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Total Synthesis of (±)-Eucophylline. A Free-Radical Approach to the Synthesis of the Azabicyclo[3.3.1]nonane Skeleton. Org Lett 2015; 17:4518-21. [PMID: 26348122 DOI: 10.1021/acs.orglett.5b02218] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The first total synthesis of eucophylline was reported in 10 steps and 10% overall yield. The naphthyridine core of eucophylline was prepared through the coupling between a strained azabicyclo[3.3.1]nonan-2-one and a trisubstituted benzonitrile, followed by a cyclization of the corresponding amidine. This coupling reaction was shown to proceed through a stable bicyclic chloroenamine intermediate. The azabicyclo[3.3.1]nonan-2-one skeleton was in turn accessible through a straightforward sequence including a free-radical three-component olefin carbo-oximation as a key step.
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41
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From the N-Heterocyclic Carbene-Catalyzed Conjugate Addition of Alcohols to the Controlled Polymerization of (Meth)acrylates. Chemistry 2015; 21:9447-53. [PMID: 26013759 DOI: 10.1002/chem.201500594] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Indexed: 11/10/2022]
Abstract
Among various N-heterocyclic carbenes (NHCs) tested, only 1,3-bis(tert-butyl)imidazol-2-ylidene (NHC(tBu) ) proved to selectively promote the catalytic conjugate addition of alcohols onto (meth)acrylate substrates. This rather rare example of NHC-catalyzed 1,4-addition of alcohols was investigated as a simple means to trigger the polymerization of both methyl methacrylate and methyl acrylate (MMA and MA, respectively). Well-defined α-alkoxy poly(methyl (meth)acrylate) (PM(M)A) chains, the molar masses of which could be controlled by the initial [(meth)acrylate]0/[ROH]0 molar ratio, were ultimately obtained in N,N-dimethylformamide at 25 °C. A hydroxyl-terminated poly(ethylene oxide) (PEO-OH) macro-initiator was also employed to directly access PEO-b-PMMA amphiphilic block copolymers. Investigations into the reaction mechanism by DFT calculations revealed the occurrence of two competitive concerted pathways, involving either the activation of the alcohol or that of the monomer by NHC(tBu) .
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Base-catalyzed intramolecular hydroamination of cyclohexa-2,5-dienes: insights into the mechanism through DFT calculations and application to the total synthesis of epi-elwesine. Chemistry 2014; 20:14771-82. [PMID: 25223607 DOI: 10.1002/chem.201403662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/10/2014] [Indexed: 11/08/2022]
Abstract
The base-catalyzed intramolecular hydroamination of 1-ethylaminocyclohexa-2,5-dienes is described. The transformation proceeds through isomerization of the cyclohexa-1,4-dienyl fragment into the corresponding conjugated 1,3-diene prior to the hydroamination step. Attaching a chiral glycinol ether auxiliary on the amino group allows the protonation to occur with complete diastereocontrol. The resulting lithium amide then adds onto the 1,3-dienyl moiety, affording the desired fused pyrrolidine ring along with the corresponding lithium allylic anion. Protonation of the latter then proceeds with high regiocontrol to favor the resulting allylic amines. In contrast, when the reaction was performed on primary amines, fused pyrrolidines bearing a homoallylic amino group were obtained. The stereochemical course of the process and determination of the reaction pathways were established based on calculations performed at the DFT level. Finally, application of the methodology to the enantioselective synthesis of (+)-epi-elwesine, a crinane alkaloid, is described.
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Organocatalyzed Step-Growth Polymerization through Desymmetrization of Cyclic Anhydrides: Synthesis of Chiral Polyesters. Chemistry 2014; 20:11946-53. [DOI: 10.1002/chem.201402373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/22/2014] [Indexed: 11/10/2022]
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45
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Synthesis of the C10-C24-bis-spiroacetal core of 13-desmethyl spirolide C based on a sila-Stetter-acetalization process. Chemistry 2014; 20:9336-41. [PMID: 24925107 DOI: 10.1002/chem.201402894] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Indexed: 11/11/2022]
Abstract
Synthesis of the bis-spiroacetal core of 13-desmethyl spirolide C has been completed based on a sila-Stetter-acetalization process. The acylsilane and enone partners in the Stetter reaction were prepared in 7 and 11 steps, respectively, from (S) and (R)-aspartic acid. The quaternary center at C19 in the enone moiety was controlled by relying on the Seebach's chiral self-reproduction method using an enantiopure (S)-lactic acid based dioxolanone. The final acid-catalyzed spiroacetalization provided the desired spiroacetal as a mixture of diastereoisomers in 13 linear steps. Whatever the conditions used, the non-natural transoid isomer was formed preferentially. However, both cisoid and transoid isomers were isolated pure and their structure assigned unambiguously through NMR spectroscopic studies.
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46
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Cyclodimerization versus Polymerization of Methyl Methacrylate Induced byN-Heterocyclic Carbenes: A Combined Experimental and Theoretical Study. Chemistry 2014; 20:3989-97. [DOI: 10.1002/chem.201304492] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Indexed: 11/09/2022]
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47
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One-Pot Synthesis and PEGylation of Hyperbranched Polyacetals with a Degree of Branching of 100%. Macromolecules 2014. [DOI: 10.1021/ma4026509] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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48
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Polyaldol Synthesis by Direct Organocatalyzed Crossed Polymerization of Bis(ketones) and Bis(aldehydes). Macromolecules 2014. [DOI: 10.1021/ma402108y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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49
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Novel green fatty acid-based bis-cyclic carbonates for the synthesis of isocyanate-free poly(hydroxyurethane amide)s. RSC Adv 2014. [DOI: 10.1039/c4ra03675a] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Novel fatty acid-based bis 5-membered carbonates for a non-isocyante route to polyurethanes.
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50
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Organocatalyzed Aldol Reaction between Pyridine-2-carbaldehydes and α-Ketoacids: A Straightforward Route towards Indolizidines and Isotetronic Acids. Chemistry 2013; 19:14532-9. [DOI: 10.1002/chem.201302264] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Indexed: 11/08/2022]
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