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Jonathan Clayden - One of the best experts on this subject based on the ideXlab platform.
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enantioselective carbolithiation of s alkenyl n aryl Thiocarbamates kinetic and thermodynamic control
Organic and Biomolecular Chemistry, 2015Co-Authors: Daniele Castagnolo, Renzo Luisi, Leonardo Degennaro, Jonathan ClaydenAbstract:The addition of n-butyllithium to alkenylThiocarbamates in the presence of (−)-sparteine or the (+)-sparteine surrogate leads to asymmetric carbolithiation, and returns enantiomerically enriched Thiocarbamate derivatives of secondary thiols. In THF, with the (+)-sparteine surrogate, in situ aryl migration leads to an enantiomerically enriched tertiary thiol derivative. Remarkably, the two pseudoenantiomeric chiral ligands do not always give enantiomeric products, probably as a result of a complex interplay of kinetic and thermodynamic control. In situ IR and NMR studies of a stable, hindered lithiated Thiocarbamate demonstrated its chemical and configurational stability over a period of hours at 0 °C.
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dihydrothiophenes containing quaternary stereogenic centres by sequential stereospecific rearrangements and ring closing metathesis
ChemInform, 2014Co-Authors: Gaelle Mingat, Joseph J W Mcdouall, Jonathan ClaydenAbstract:The reaction of alcohol (I) with N,N′-thiocarbonyldiimidazole is accompanied by a [3,4]-sigmatropic rearrangement to afford imidazoles (III), which are readily converted into Thiocarbamates (V).
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tertiary thiols from allylic Thiocarbamates by tandem enantioselective 3 3 sigmatropic rearrangement and stereospecific arylation
ChemInform, 2014Co-Authors: Gaelle Mingat, Paul Maclellan, Marju Laars, Jonathan ClaydenAbstract:Enantiomerically enriched N-aryl allylic Thiocarbamates (II) are obtained via Pd-catalyzed [3,3]-sigmatropic rearrangement.
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dihydrothiophenes containing quaternary stereogenic centres by sequential stereospecific rearrangements and ring closing metathesis
Chemical Communications, 2014Co-Authors: Gaelle Mingat, Joseph J W Mcdouall, Jonathan ClaydenAbstract:Stereospecific [3,3]-sigmatropic rearrangement of O-substituted Thiocarbamate derivatives of enantiopure allylic alcohols provides allylic Thiocarbamates as single enantiomers. Intramolecular arylation by rearrangement of their allyllithium derivatives provides allylic tertiary thiols. Allylation and ring-closing metathesis gives 2,5-dihydrothiophenes containing sulfur-bearing quaternary centres.
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tertiary thiols from allylic Thiocarbamates by tandem enantioselective 3 3 sigmatropic rearrangement and stereospecific arylation
Organic Letters, 2014Co-Authors: Gaelle Mingat, Paul Maclellan, Marju Laars, Jonathan ClaydenAbstract:The synthesis of tertiary thiols in enantiomerically enriched form is accomplished by lithiation of enantiomerically enriched N-aryl allylic Thiocarbamates. Formation of an allyllithium derivative promotes intramolecular N to C aryl migration to the position α to sulfur, generally with good stereospecificity. The substrates may themselves be obtained by Pd-catalyzed enantioselective [3,3]-sigmatropic rearrangement of N-aryl O-allyl Thiocarbamates. Solvolysis of the product Thiocarbamates yields tertiary thiols, which may be converted to sulfide derivatives.
Gaelle Mingat - One of the best experts on this subject based on the ideXlab platform.
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dihydrothiophenes containing quaternary stereogenic centres by sequential stereospecific rearrangements and ring closing metathesis
ChemInform, 2014Co-Authors: Gaelle Mingat, Joseph J W Mcdouall, Jonathan ClaydenAbstract:The reaction of alcohol (I) with N,N′-thiocarbonyldiimidazole is accompanied by a [3,4]-sigmatropic rearrangement to afford imidazoles (III), which are readily converted into Thiocarbamates (V).
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tertiary thiols from allylic Thiocarbamates by tandem enantioselective 3 3 sigmatropic rearrangement and stereospecific arylation
ChemInform, 2014Co-Authors: Gaelle Mingat, Paul Maclellan, Marju Laars, Jonathan ClaydenAbstract:Enantiomerically enriched N-aryl allylic Thiocarbamates (II) are obtained via Pd-catalyzed [3,3]-sigmatropic rearrangement.
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dihydrothiophenes containing quaternary stereogenic centres by sequential stereospecific rearrangements and ring closing metathesis
Chemical Communications, 2014Co-Authors: Gaelle Mingat, Joseph J W Mcdouall, Jonathan ClaydenAbstract:Stereospecific [3,3]-sigmatropic rearrangement of O-substituted Thiocarbamate derivatives of enantiopure allylic alcohols provides allylic Thiocarbamates as single enantiomers. Intramolecular arylation by rearrangement of their allyllithium derivatives provides allylic tertiary thiols. Allylation and ring-closing metathesis gives 2,5-dihydrothiophenes containing sulfur-bearing quaternary centres.
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tertiary thiols from allylic Thiocarbamates by tandem enantioselective 3 3 sigmatropic rearrangement and stereospecific arylation
Organic Letters, 2014Co-Authors: Gaelle Mingat, Paul Maclellan, Marju Laars, Jonathan ClaydenAbstract:The synthesis of tertiary thiols in enantiomerically enriched form is accomplished by lithiation of enantiomerically enriched N-aryl allylic Thiocarbamates. Formation of an allyllithium derivative promotes intramolecular N to C aryl migration to the position α to sulfur, generally with good stereospecificity. The substrates may themselves be obtained by Pd-catalyzed enantioselective [3,3]-sigmatropic rearrangement of N-aryl O-allyl Thiocarbamates. Solvolysis of the product Thiocarbamates yields tertiary thiols, which may be converted to sulfide derivatives.
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Tertiary Thiols from Allylic Thiocarbamates by Tandem Enantioselective [3,3]-Sigmatropic Rearrangement and Stereospecific Arylation
2014Co-Authors: Gaelle Mingat, Paul Maclellan, Marju Laars, Jonathan ClaydenAbstract:The synthesis of tertiary thiols in enantiomerically enriched form is accomplished by lithiation of enantiomerically enriched N-aryl allylic Thiocarbamates. Formation of an allyllithium derivative promotes intramolecular N to C aryl migration to the position α to sulfur, generally with good stereospecificity. The substrates may themselves be obtained by Pd-catalyzed enantioselective [3,3]-sigmatropic rearrangement of N-aryl O-allyl Thiocarbamates. Solvolysis of the product Thiocarbamates yields tertiary thiols, which may be converted to sulfide derivatives
Yingwei Zhao - One of the best experts on this subject based on the ideXlab platform.
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Thiocarbamate directed tandem olefination intramolecular sulfuration of two ortho c h bonds application to synthesis of a cox 2 inhibitor
Organic Letters, 2018Co-Authors: Yingwei Zhao, Shaoyu Mai, Qiuling SongAbstract:A palladium-catalyzed dual ortho C–H bond activation of aryl Thiocarbamates is developed. This tandem reaction initiates by Thiocarbamate-directed ortho C–H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C–H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor.
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Thiocarbamate-Directed Tandem Olefination–Intramolecular Sulfuration of Two Ortho C–H Bonds: Application to Synthesis of a COX‑2 Inhibitor
2018Co-Authors: Yingwei Zhao, Shaoyu Mai, Qiuling SongAbstract:A palladium-catalyzed dual ortho C–H bond activation of aryl Thiocarbamates is developed. This tandem reaction initiates by Thiocarbamate-directed ortho C–H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C–H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor
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access to coumarins by rhodium catalyzed oxidative annulation of aryl Thiocarbamates with internal alkynes
ChemInform, 2015Co-Authors: Yingwei Zhao, Lei YangAbstract:A wide range of 3,4-disubstituted coumarins are efficiently obtained by exploitation of a Thiocarbamate group directed C—H bond activation, an annulation with an alkyne, and a desulfurization.
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oxygen sulfur rearrangement in the reaction of Thiocarbamate imidazolium ylide with arylaldehyde
Organic and Biomolecular Chemistry, 2012Co-Authors: Yingwei Zhao, Lei Yang, Min Lei, Feng Han, Chungu XiaAbstract:The nucleophilic addition of Thiocarbamate imidazolium ylide to aldehyde triggered sequential intramolecular N to O migration of thiocarbonyl amide group and reversible oxygen–sulfur rearrangement to afford 2-imidazolium alkylcarbamothioate. The ortho group on phenyl of aldehyde strongly affects the balance of the O- to S-rearrangement.
Qiuling Song - One of the best experts on this subject based on the ideXlab platform.
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Thiocarbamate directed tandem olefination intramolecular sulfuration of two ortho c h bonds application to synthesis of a cox 2 inhibitor
Organic Letters, 2018Co-Authors: Yingwei Zhao, Shaoyu Mai, Qiuling SongAbstract:A palladium-catalyzed dual ortho C–H bond activation of aryl Thiocarbamates is developed. This tandem reaction initiates by Thiocarbamate-directed ortho C–H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C–H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor.
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Thiocarbamate-Directed Tandem Olefination–Intramolecular Sulfuration of Two Ortho C–H Bonds: Application to Synthesis of a COX‑2 Inhibitor
2018Co-Authors: Yingwei Zhao, Shaoyu Mai, Qiuling SongAbstract:A palladium-catalyzed dual ortho C–H bond activation of aryl Thiocarbamates is developed. This tandem reaction initiates by Thiocarbamate-directed ortho C–H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C–H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor
Rui Wang - One of the best experts on this subject based on the ideXlab platform.
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Direct organocatalytic asymmetric aldol reaction of alpha-isothiocyanato imides to alpha-ketoesters under low ligand loading: a doubly stereocontrolled approach to cyclic Thiocarbamates bearing chiral quaternary stereocenters.
Organic letters, 2010Co-Authors: Xianxing Jiang, Zhang, Yiming Cao, Fang‐fang Shen, Rui WangAbstract:The first doubly stereocontrolled organocatalytic asymmetric aldol reaction of alpha-isothiocyanato imides with alpha-ketoesters by using rosin-derived tertiary amine-thiourea under low ligand loading to form cyclic Thiocarbamates bearing quaternary stereogenic centers with high levels of enantio- and diastereoselectivity (up to 99% ee, and 97:3 dr) is presented. This reaction provides a convenient doubly stereocontrolled method to access synthetic useful multiply substituted cyclic Thiocarbamates with high optical purity.
