Cobalt-Catalyzed Intermolecular Hydroacylation of Olefins through Chelation-Assisted Imidoyl C–H Activation
作者:Junfeng Yang、Yuan Wah Seto、Naohiko Yoshikai
DOI:10.1021/acscatal.5b00581
日期:2015.5.1
A low-valent cobalt catalyst generated from cobalt(II) bromide, a diphosphine ligand, and zinc powder promotes intermolecular hydroacylation of olefins using N-3-picolin-2-yl aldimines as aldehyde equivalents, which affords, upon acidic hydrolysis, ketone products in moderate to good yields with high linear selectivity. The reaction is applicable to styrenes, vinylsilanes, and aliphatic olefins as well as to various aryl and heteroaryl aldimines. The cobalt catalysis features a distinctively lower reaction temperature (60 degrees C) compared with those required for the same type of transformations catalyzed by rhodium complexes (typically 130-150 degrees C).