The Experts below are selected from a list of 474 Experts worldwide ranked by ideXlab platform
Koji Yamakawa - One of the best experts on this subject based on the ideXlab platform.
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Favorskii Rearrangement and carbon carbon bond cleavage of α chloro α sulfonyl ketones a synthesis of carboxylic acids and their derivatives from aldehydes and ketones
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:A method for synthesizing carboxylic acids and their derivatives from aldehydes and ketones via α-chloro-α-sulfonyl ketones is described. Acyclic α-chloro-α-sulfonyl ketones were synthesized from aldehydes and 1-chloroalkyl p-tolyl sulfoxides with carbon–carbon coupling in good overall yields. Cyclic α-chloro-α-sulfonyl ketones were synthesized from cyclic ketones in three steps in high overall yields. The Favorskii Rearrangement of both acyclic- and cyclic α-chloro-α-sulfonyl ketones with sodium hydride in the presence of amine gave β-sulfonyl amides with skeletal Rearrangement in good to excellent yield. Amides and α,β-unsaturated amides were synthesized from the β-sulfonyl amides. Treatment of the cyclic α-chloro-α-sulfonyl ketones with alkoxides and hydroxide gave carboxylic esters and acids with cleavage of the ring in good to excellent yields.
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the asymmetric Favorskii Rearrangement a synthesis of optically active α alkyl amides from aldehydes and 1 chloroalkyl p tolyl sulfoxide
Tetrahedron Letters, 1993Co-Authors: Tsuyoshi Satoh, Shigeyasu Motohashi, Sachiko Kimura, Norio Tokutake, Koji YamakawaAbstract:Abstract The first asymmetric Favorskii Rearrangement is described. Optically active α-alkyl amides of enantiomeric excess up to 94% were realized from aldehydes and optically active (−)-1-chloroalkyl p-tolyl sulfoxides via the Favorskii Rearrangement of optically active α-chloro α-sulfonyl ketones.
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The asymmetric Favorskii Rearrangement: A synthesis of optically active α-alkyl amides from aldehydes and (−)-1-chloroalkyl p-tolyl sulfoxide
Tetrahedron Letters, 1993Co-Authors: Tsuyoshi Satoh, Shigeyasu Motohashi, Sachiko Kimura, Norio Tokutake, Koji YamakawaAbstract:Abstract The first asymmetric Favorskii Rearrangement is described. Optically active α-alkyl amides of enantiomeric excess up to 94% were realized from aldehydes and optically active (−)-1-chloroalkyl p-tolyl sulfoxides via the Favorskii Rearrangement of optically active α-chloro α-sulfonyl ketones.
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Favorskii Rearrangement and Carbon–Carbon Bond-Cleavage of α-Chloro-α-sulfonyl Ketones: A Synthesis of Carboxylic Acids and Their Derivatives from Aldehydes and Ketones
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:A method for synthesizing carboxylic acids and their derivatives from aldehydes and ketones via α-chloro-α-sulfonyl ketones is described. Acyclic α-chloro-α-sulfonyl ketones were synthesized from aldehydes and 1-chloroalkyl p-tolyl sulfoxides with carbon–carbon coupling in good overall yields. Cyclic α-chloro-α-sulfonyl ketones were synthesized from cyclic ketones in three steps in high overall yields. The Favorskii Rearrangement of both acyclic- and cyclic α-chloro-α-sulfonyl ketones with sodium hydride in the presence of amine gave β-sulfonyl amides with skeletal Rearrangement in good to excellent yield. Amides and α,β-unsaturated amides were synthesized from the β-sulfonyl amides. Treatment of the cyclic α-chloro-α-sulfonyl ketones with alkoxides and hydroxide gave carboxylic esters and acids with cleavage of the ring in good to excellent yields.
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Favorskii Rearrangement of α-chloro β-keto sulfones with amines: a new synthesis of amides and α,β-unsaturated amides from aldehydes and ketons
Tetrahedron Letters, 1992Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:Abstract The Favorskii Rearrangement of α-chloro β-keto sulfones, which are easily synthesized from aldehydes and ketones, with amines gives β-sulfonyl amides in good yield. These β-sulfonyl amides are converted to amides and α,β-unsaturated amides by reduction or elimination of the sulfonyl group.
Michael Harmata - One of the best experts on this subject based on the ideXlab platform.
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Addition of Functionalized Nucleophiles to a Bridgehead Bromoketone
Synthesis, 2007Co-Authors: Michael Harmata, Sumrit WacharasindhuAbstract:The reaction of bromoketone 1 with a variety of functionalized organolithiums is presented. In most cases, carbonyl addition followed by quasi-Favorskii Rearrangement takes place to afford the Rearrangement product in good yield. The utility of products from such a reaction is demonstrated in the synthesis of 22 from 14 via allylation and ring-opening/ring-closing metathesis.
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The [4 + 3]-Cycloaddition/Quasi-Favorskii Process. Synthesis of the Carbocyclic Core of Tricycloclavulone
Organic letters, 2005Co-Authors: Michael Harmata, Sumrit WacharasindhuAbstract:The [4 + 3]-cycloadduct derived from the reaction of 2,5-dibromocyclopentanone with cyclopentadiene was converted via a quasi-Favorskii Rearrangement and ring-opening, ring-closing metathesis sequence to the carbocyclic core of the prostanoid tricycloclavulone.
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The Addition of sp2- and sp-Hybridized Nucleophiles to a Bridgehead Bromoketone
The Journal of organic chemistry, 2005Co-Authors: Michael Harmata, Sumrit WacharasindhuAbstract:The reaction of various sp2- and sp-hybridized organolithium species with bromoketone 1 is presented. In most cases, control over the course of the process is possible and products from simple addition, addition followed by a quasi-Favorskii Rearrangement or addition, Rearrangement, and addition can be selectively prepared.
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A 4+3 Cycloaddition Approach to the Synthesis of (±)-Sterpurene
Organic letters, 2003Co-Authors: Michael Harmata, Gary BohnertAbstract:A synthesis of the sesquiterpene sterpurene is presented. Key steps include a 4+3 cycloaddition reaction and a quasi-Favorskii Rearrangement.
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Intramolecular 4+3 cycloadditions. A cyclohexenyl cation, its halogenated congener and a quasi-Favorskii Rearrangement
Tetrahedron Letters, 2002Co-Authors: Michael Harmata, László Kürti, Gary Bohnert, Charles L. BarnesAbstract:Abstract Treatment of alkoxycyclohexenols bearing a tethered diene substituent with a Lewis acid results in intramolecular 4+3 cycloaddition with complete endo selectivity. A cycloadduct bearing a bromo substituent at a bridgehead position undergoes a quasi-Favorskii Rearrangement in near quantitative yield upon reaction with lithium aluminum hydride.
Tsuyoshi Satoh - One of the best experts on this subject based on the ideXlab platform.
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Favorskii Rearrangement and carbon carbon bond cleavage of α chloro α sulfonyl ketones a synthesis of carboxylic acids and their derivatives from aldehydes and ketones
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:A method for synthesizing carboxylic acids and their derivatives from aldehydes and ketones via α-chloro-α-sulfonyl ketones is described. Acyclic α-chloro-α-sulfonyl ketones were synthesized from aldehydes and 1-chloroalkyl p-tolyl sulfoxides with carbon–carbon coupling in good overall yields. Cyclic α-chloro-α-sulfonyl ketones were synthesized from cyclic ketones in three steps in high overall yields. The Favorskii Rearrangement of both acyclic- and cyclic α-chloro-α-sulfonyl ketones with sodium hydride in the presence of amine gave β-sulfonyl amides with skeletal Rearrangement in good to excellent yield. Amides and α,β-unsaturated amides were synthesized from the β-sulfonyl amides. Treatment of the cyclic α-chloro-α-sulfonyl ketones with alkoxides and hydroxide gave carboxylic esters and acids with cleavage of the ring in good to excellent yields.
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the asymmetric Favorskii Rearrangement a synthesis of optically active α alkyl amides from aldehydes and 1 chloroalkyl p tolyl sulfoxide
Tetrahedron Letters, 1993Co-Authors: Tsuyoshi Satoh, Shigeyasu Motohashi, Sachiko Kimura, Norio Tokutake, Koji YamakawaAbstract:Abstract The first asymmetric Favorskii Rearrangement is described. Optically active α-alkyl amides of enantiomeric excess up to 94% were realized from aldehydes and optically active (−)-1-chloroalkyl p-tolyl sulfoxides via the Favorskii Rearrangement of optically active α-chloro α-sulfonyl ketones.
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The asymmetric Favorskii Rearrangement: A synthesis of optically active α-alkyl amides from aldehydes and (−)-1-chloroalkyl p-tolyl sulfoxide
Tetrahedron Letters, 1993Co-Authors: Tsuyoshi Satoh, Shigeyasu Motohashi, Sachiko Kimura, Norio Tokutake, Koji YamakawaAbstract:Abstract The first asymmetric Favorskii Rearrangement is described. Optically active α-alkyl amides of enantiomeric excess up to 94% were realized from aldehydes and optically active (−)-1-chloroalkyl p-tolyl sulfoxides via the Favorskii Rearrangement of optically active α-chloro α-sulfonyl ketones.
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Favorskii Rearrangement and Carbon–Carbon Bond-Cleavage of α-Chloro-α-sulfonyl Ketones: A Synthesis of Carboxylic Acids and Their Derivatives from Aldehydes and Ketones
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:A method for synthesizing carboxylic acids and their derivatives from aldehydes and ketones via α-chloro-α-sulfonyl ketones is described. Acyclic α-chloro-α-sulfonyl ketones were synthesized from aldehydes and 1-chloroalkyl p-tolyl sulfoxides with carbon–carbon coupling in good overall yields. Cyclic α-chloro-α-sulfonyl ketones were synthesized from cyclic ketones in three steps in high overall yields. The Favorskii Rearrangement of both acyclic- and cyclic α-chloro-α-sulfonyl ketones with sodium hydride in the presence of amine gave β-sulfonyl amides with skeletal Rearrangement in good to excellent yield. Amides and α,β-unsaturated amides were synthesized from the β-sulfonyl amides. Treatment of the cyclic α-chloro-α-sulfonyl ketones with alkoxides and hydroxide gave carboxylic esters and acids with cleavage of the ring in good to excellent yields.
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Favorskii Rearrangement of α-chloro β-keto sulfones with amines: a new synthesis of amides and α,β-unsaturated amides from aldehydes and ketons
Tetrahedron Letters, 1992Co-Authors: Tsuyoshi Satoh, Kazuko Oguro, Jun-ichi Shishikura, Naomi Kanetaka, Reiko Okada, Koji YamakawaAbstract:Abstract The Favorskii Rearrangement of α-chloro β-keto sulfones, which are easily synthesized from aldehydes and ketones, with amines gives β-sulfonyl amides in good yield. These β-sulfonyl amides are converted to amides and α,β-unsaturated amides by reduction or elimination of the sulfonyl group.
Seiji Iwasa - One of the best experts on this subject based on the ideXlab platform.
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williamson ether synthesis with phenols at a tertiary stereogenic carbon formal enantioselective phenoxylation of β keto esters
Chemistry: A European Journal, 2015Co-Authors: Kazutaka Shibatomi, Manato Kotozaki, Nozomi Sasaki, Ikuhide Fujisawa, Seiji IwasaAbstract:The enantioselective formation of α-aryloxy-β-keto esters is described for the first time. Lewis acid catalyzed enantioselective chlorination of β-keto esters and subsequent SN 2 reactions with phenols yielded α-aryloxy-β-keto esters with up to 96% ee. Favorskii Rearrangement of α-chloro-β-keto esters was also found to give 1,2-diesters with slightly reduced enantiopurity.
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Williamson Ether Synthesis with Phenols at a Tertiary Stereogenic Carbon: Formal Enantioselective Phenoxylation of β‐Keto Esters
Chemistry: A European Journal, 2015Co-Authors: Kazutaka Shibatomi, Manato Kotozaki, Nozomi Sasaki, Ikuhide Fujisawa, Seiji IwasaAbstract:The enantioselective formation of α-aryloxy-β-keto esters is described for the first time. Lewis acid catalyzed enantioselective chlorination of β-keto esters and subsequent SN 2 reactions with phenols yielded α-aryloxy-β-keto esters with up to 96% ee. Favorskii Rearrangement of α-chloro-β-keto esters was also found to give 1,2-diesters with slightly reduced enantiopurity.
Kazutaka Shibatomi - One of the best experts on this subject based on the ideXlab platform.
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williamson ether synthesis with phenols at a tertiary stereogenic carbon formal enantioselective phenoxylation of β keto esters
Chemistry: A European Journal, 2015Co-Authors: Kazutaka Shibatomi, Manato Kotozaki, Nozomi Sasaki, Ikuhide Fujisawa, Seiji IwasaAbstract:The enantioselective formation of α-aryloxy-β-keto esters is described for the first time. Lewis acid catalyzed enantioselective chlorination of β-keto esters and subsequent SN 2 reactions with phenols yielded α-aryloxy-β-keto esters with up to 96% ee. Favorskii Rearrangement of α-chloro-β-keto esters was also found to give 1,2-diesters with slightly reduced enantiopurity.
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Williamson Ether Synthesis with Phenols at a Tertiary Stereogenic Carbon: Formal Enantioselective Phenoxylation of β‐Keto Esters
Chemistry: A European Journal, 2015Co-Authors: Kazutaka Shibatomi, Manato Kotozaki, Nozomi Sasaki, Ikuhide Fujisawa, Seiji IwasaAbstract:The enantioselective formation of α-aryloxy-β-keto esters is described for the first time. Lewis acid catalyzed enantioselective chlorination of β-keto esters and subsequent SN 2 reactions with phenols yielded α-aryloxy-β-keto esters with up to 96% ee. Favorskii Rearrangement of α-chloro-β-keto esters was also found to give 1,2-diesters with slightly reduced enantiopurity.
