Development of transition metal-catalyzed C-S and C-C cross-coupling reactions
type: CreativeWork
description: The transition-metal-catalyzed carbon-carbon and carbon-heteroatom bond forming reactions are important and fundamental transformations in synthetic organic chemistry. These reactions have been widely used for a variety of cross-coupling reactions of aryl halides in the processes of C?C, C?N and C?S bond forming reactions. In this dissertation, we have developed new cross-coupling protocols for the synthesis of vinyl sulfides, benzothiazoles and benzoxazoles, using transition-metal-based catalysis. Furthermore, the mechanism of these cross-coupling reactions has also been investigated. Although numerous methods have been developed for the stereoselective synthesis of (E)-vinyl sulfides, it has been challenging to prepare Z-isomers. Chapter 2 describes a novel method for the synthesis of vinyl sulfides by the decarboxylative cross-coupling of arylpropiolic acids with thiols using copper(I) salts as catalysts. In the presence of CuI and Cs2CO3, a number of thiols reacted with arylpropiolic acids to afford the corresponding vinyl sulfides in high yields with high stereoselectivity for Z-isomers. This work suggests the potential for broad generality and promotes an economically feasible route to large scale synthesis of vinyl sulfides without the need of organohalide reagents. Chapter 3 deals a general and highly efficient method for direct thiolation of heterocyclic C?H bond with thiols. Without the need of organohalide precursors, a variety of 2-thio-substituted benzothiazoles, imidazoles and indoles are synthesized in one step in the presence of CuI, 2,2'-bipyridine, and Na2CO3. Both aliphatic and aromatic thiols are compatible with this method, resulting in the formation of corresponding cross-coupling heterocycles in good yields. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimenta results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bident…
abstract: The transition-metal-catalyzed carbon-carbon and carbon-heteroatom bond forming reactions are important and fundamental transformations in synthetic organic chemistry. These reactions have been widely used for a variety of cross-coupling reactions of aryl halides in the processes of C?C, C?N and C?S bond forming reactions. In this dissertation, we have developed new cross-coupling protocols for the synthesis of vinyl sulfides, benzothiazoles and benzoxazoles, using transition-metal-based catalysis. Furthermore, the mechanism of these cross-coupling reactions has also been investigated. Although numerous methods have been developed for the stereoselective synthesis of (E)-vinyl sulfides, it has been challenging to prepare Z-isomers. Chapter 2 describes a novel method for the synthesis of vinyl sulfides by the decarboxylative cross-coupling of arylpropiolic acids with thiols using copper(I) salts as catalysts. In the presence of CuI and Cs2CO3, a number of thiols reacted with arylpropiolic acids to afford the corresponding vinyl sulfides in high yields with high stereoselectivity for Z-isomers. This work suggests the potential for broad generality and promotes an economically feasible route to large scale synthesis of vinyl sulfides without the need of organohalide reagents. Chapter 3 deals a general and highly efficient method for direct thiolation of heterocyclic C?H bond with thiols. Without the need of organohalide precursors, a variety of 2-thio-substituted benzothiazoles, imidazoles and indoles are synthesized in one step in the presence of CuI, 2,2'-bipyridine, and Na2CO3. Both aliphatic and aromatic thiols are compatible with this method, resulting in the formation of corresponding cross-coupling heterocycles in good yields. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimenta results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bident…
author: SADANANDA RANJIT
keywords: Cross-Couplings, Thiols, Benzothiazoles, Decarboxylation, C-H activation, Pd-Naowires
date published: 2011-01-13
date modified: 2026-07-24T03:33:34Z
provider: National University of Singapore
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: National University of Singapore