The Merger of Transition Metal and Photocatalysis: Recent Advances and Prospects in Asymmetric Intermolecular 1,2-Difunctionalization of Alkenes

Unsaturated carbon–carbon bonds are fundamental building blocks in organic compounds. The difunctionalization of olefins allows for the rapid construction of drugs and complex molecular architectures. This transformation, which simultaneously installs two distinct functional groups across a carbon–carbon double bond, has therefore emerged as prominent research frontier in organic chemistry. In recent years, the synergy between photoredox and transition metal catalysis has emerged as a powerful and sustainable platform for constructing C-X bonds. This review covers advances since 2018 in the asymmetric difunctionalization of olefins enabled by synergistic visible light photoredox and transition metal catalysis, encompassing the construction of both carbon–carbon and carbon–heteroatom bonds. It systematically summarizes the reaction conditions, substrate scope, mechanisms, and merits and limitations of these catalytic systems, aiming to provide a useful reference for researchers in this field.