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.