title: An efficient route to regioselective functionalization of benzo[b]thiophenes via palladium-catalyzed decarboxylative Heck coupling reactions: insights from experiment and computation.
abstract: Pd-catalyzed decarboxylative Heck-type coupling of 3-chlorobenzo[b]thiophene-2-carboxylic acids with styrenes have been developed as an efficient strategy for the construction of functionalized benzo[b]thiophenes. Theoretical analysis shows that AgCl generated during the reaction, instead of Pd, π-coordinates with the carboxyl O atom, making easy the rate-determining CO2 dissociation. The divergent reactivities of the Cl-substituted and H-substituted 3-benzo[b]thiophene-2-carboxylic acids are mainly due to the presence of the Cl substituent, which reduces the adjacent π-π interplay, thereby significantly contributing to decarboxylation. Therefore, the presence of both AgCl and the Cl substituent are of key importance in ensuring the occurrence of the reaction under the given conditions.
authors.affiliation: The Key Laboratory of Life-Organic Analysis and Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, Shandong, China. huawang_qfnu@126.com.
authors.forename: Daoshan
authors.initials: D
authors.lastname: Yang
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Liu
authors.forename: Pengfei
authors.initials: P
authors.lastname: Sun
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Mingyang
authors.initials: M
authors.lastname: Sun
authors.forename: Guang
authors.initials: G
authors.lastname: Chen
authors.forename: Siwei
authors.initials: S
authors.lastname: Bi
authors.forename: Hua
authors.initials: H
authors.lastname: Wang