Photocatalytic hydrotrichloromethylation of unactivated alkenes with chloroform†

Abstract

Trichloromethyl compounds are essential constituents in synthetic and medicinal chemistry. Hydrotrichloromethylation of alkenes represents the most straightforward approach for synthesizing trichloromethyl compounds. Nonetheless, the applicability of prior synthesis methodologies in this regard was notably constrained by the superstoichiometric use of excessive radical initiators and the formation of alkene polymers or dichloromethylation by-products. Herein, an innovative and facile photocatalytic hydrotrichloromethylation of unactivated alkenes using chloroform via base-enabled photoinduced single-electron transfer is demonstrated. This strategy offers an expedited way of synthesizing trichloromethyl compounds with broad applicability and mild conditions while addressing the limitations of previous synthesis methods. Meanwhile, mechanistic studies support the process of chloroform deprotonation followed by oxidation.