Base-Promoted Electrochemical CoII -catalyzed Enantioselective C-H Oxygenation

Angew Chem Int Ed Engl. 2023 May 15;62(21):e202302964. doi: 10.1002/anie.202302964. Epub 2023 Apr 13.

Abstract

Metalla-electrocatalyzed C-H oxygenation represents one of the most straightforward and sustainable approaches to access valuable oxygenated molecules. Despite the significant advances, the development of enantioselective electrochemical C-H oxygenation reaction is very challenging and remains elusive. Herein, we described the first electrochemical CoII -catalyzed enantioselective C-H alkoxylation. A broad range of enantioenriched alkoxylated phosphinamides were obtained in good yields with excellent enantioselectivities (up to 98 % yield and >99 % ee). An unusual cobalt(III) alcohol complex was prepared and fully characterized, which was proven to be a key intermediate of this C-H alkoxylation reaction. Mechanistic studies revealed that the oxidation of CoIII to CoIV was facilitated by a base and the whole process proceeded through a cobalt(III/IV/II) catalytic cycle.

Keywords: Cobalt; C−H Activation; Electrochemistry; Enantioselectivity; Oxygenation.