Electrochemical Vicinal C-H Difunctionalization of Saturated Azaheterocycles

J Am Chem Soc. 2024 Jan 24;146(3):1794-1798. doi: 10.1021/jacs.3c12336. Epub 2024 Jan 8.

Abstract

A method to functionalize two vicinal C-H bonds of saturated azaheterocycles is described. The procedure involves subjecting the substrate to a mixture of hydrochloric acid, acetic acid, and acetic anhydride in an undivided electrochemical cell at a constant current, resulting in stereoselective conversion to the corresponding α-acetoxy-β-chloro derivative. The α-position can be readily substituted with a range of other groups, including alkyl, aryl, allyl, alkynyl, alkoxy, or azido functionalities. Furthermore, we demonstrate that the β-chloro position can be engaged in Suzuki cross-coupling. This protocol thus enables the rapid diversification of simple five-, six-, and seven-membered saturated azaheterocycles at two adjacent positions.