Cobalt-catalyzed oxidative esterification of allylic/benzylic C(sp3)-H bonds

A protocol for the cobalt-catalyzed oxidative esterification of allylic/benzylic C(sp(3))-H bonds with carboxylic acids was developed in this work. Mechanistic studies revealed that C(sp(3))-H bond activation in the hydrocarbon was the turnover-limiting step and the in-situ formed [Co(III)]Ot-Bu did not engage in hydrogen atom abstraction (HAA) of a C H bond. This protocol was successfully incorporated into a synthetic pathway to beta-damascenone that avoided the use of NBS. (C) 2017 Elsevier Ltd. All rights reserved.