Cobalt-catalyzed intermolecular hydroacylation of olefins through chelation-assisted imidoyl C-H activation

• Main Authors: Yang, Junfeng, Seto, Yuan Wah, Yoshikai, Naohiko
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2015
• Subjects: DRNTU::Science::Chemistry::Organic chemistry
• Online Access: https://hdl.handle.net/10356/79348; http://hdl.handle.net/10220/38495
• Institution: Nanyang Technological University

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 °C) compared with those required for the same type of transformations catalyzed by rhodium complexes (typically 130–150 °C).