Activation Strategies for Alkyl Precursors in Achieving C(sp³)–C(sp³) Cross-Coupling via Metallaphotoredox Catalysis

C(sp3)–C(sp3) bond formation is gaining more prominence, especially with a growing emphasis on building three-dimensional chemical space in bioactive molecules, fine chemicals, and agrichemicals. Metallaphotoredox catalysis has emerged as an effective strategy for designing processes using diverse C(sp3) precursors well suited for 1e– radical chemistry. This review summarizes the latest advancement in metallaphotoredox catalysis, addressing the long-standing challenges in C(sp3)–C(sp3) cross-coupling, with a focus on the classification of reactions based on the distinct modes of activation of C(sp3) precursor upon entering the catalytic cycle.