Mesoionic Carbene-Catalyzed Formyl Alkylation of Aldehydes

Ketones are among the most useful functional groups in organic synthesis, and they are commonly encountered in a broad range of compounds with various applications. Herein, we describe the mesoionic carbene-catalyzed coupling reaction of aldehydes with non-activated secondary and even primary alkyl halides. This metal-free method utilizes deprotonated Breslow intermediates derived from mesoionic carbenes (MICs), which act as super electron donors and induce the single-electron reduction of alkyl halides. This mild coupling reaction has a broad substrate scope and tolerates many functional groups, which allows to prepare a diversity of simple ketones as well as bio-active molecules by late-stage functionalization.

Automated summary

In this paper, a metal-free method using deprotonated Breslow intermediates derived from mesoionic carbenes (MICs) as super electron donors was described for the coupling reaction of aldehydes with non-activated secondary and primary alkyl halides. This mild coupling reaction has a broad substrate scope and tolerates many functional groups, enabling the synthesis of various simple ketones and bio-active molecules through late-stage functionalization.