Enantioselective Construction of Quaternary Stereocenters via Cooperative Photoredox/Fe/Chiral Primary Amine Triple Catalysis

J Am Chem Soc. 2024 Apr 3;146(13):9404-9412. doi: 10.1021/jacs.4c01842. Epub 2024 Mar 19.

Abstract

The catalytic and enantioselective construction of quaternary (all-carbon substituents) stereocenters poses a formidable challenge in organic synthesis due to the hindrance caused by steric factors. One conceptually viable and potentially versatile approach is the coupling of a C-C bond through an outer-sphere mechanism, accompanied by the realization of enantiocontrol through cooperative catalysis; however, examples of such processes are yet to be identified. Herein, we present such a method for creating different compounds with quaternary stereocenters by photoredox/Fe/chiral primary amine triple catalysis. This approach facilitates the connection of an unactivated alkyl source with a tertiary alkyl moiety, which is also rare. The scalable process exhibits mild conditions, does not necessitate the use of a base, and possesses a good functional-group tolerance. Preliminary investigations into the underlying mechanisms have provided valuable insights into the reaction pathway.