Electrocatalytic Activation of Donor-Acceptor Cyclopropanes and Cyclobutanes: An Alternative C(sp3 )-C(sp3 ) Cleavage Mode

Angew Chem Int Ed Engl. 2021 Jul 12;60(29):15928-15934. doi: 10.1002/anie.202101477. Epub 2021 Jun 16.

Abstract

We describe the first electrochemical activation of D-A cyclopropanes and D-A cyclobutanes leading after C(sp3 )-C(sp3 ) cleavage to the formation of highly reactive radical cations. This concept is utilized to formally insert molecular oxygen after direct or DDQ-assisted anodic oxidation of the strained carbocycles, delivering β- and γ-hydroxy ketones and 1,2-dioxanes electrocatalytically. Furthermore, insights into the mechanism of the oxidative process, obtained experimentally and by additional quantum-chemical calculations are presented. The synthetic potential of the reaction products is demonstrated by diverse derivatizations.

Keywords: C(sp3)−C(sp3) cleavage; cyclobutanes; cyclopropanes; donor-acceptor systems; synthetic electrochemistry.