Oxidative Alkane C−H Alkoxycarbonylation

Abstract

Directly utilizing a chemical feedstock to construct valuable compounds is an attractive prospect in organic synthesis. In particular, the combination of C(sp(3) )-H activation and oxidative carbonylation involving alkanes and CO gas is a promising and efficient method to synthesize carbonyl derivatives. However, due to the high C-H bond dissociation energy and low polarity of unactivated alkanes, the carbonylation of unactivated C(sp(3) )-H bonds still remains a great challenge. In this work, we introduce a palladium-catalyzed radical oxidative alkoxycarbonylation of alkanes to prepare numerous alkyl carboxylates. Various alkanes and alcohols were compatible, generating the desired products in up to 94 % yield. Remarkably, ethane, a constituent of natural gas, could be employed as a substrate under the standard reaction conditions. Preliminary mechanistic studies revealed a probable palladium-catalyzed radical process.