Cooperative NHC and Photoredox Dual Catalysis for the Construction of Carbonyl Compounds

Visible-light-promoted radical reactions have significantly influenced modern synthetic organic chemistry over the past three decades. In particular, the dual catalytic methods combining N-heterocyclic carbenes (NHCs) with metal-based (Ir, Ru) photocatalysts have emerged as a powerful synthetic strategy for efficiently constructing valuable carbonyl compounds. This synergistic methodology has revealed great potential in pharmaceutical and materials science applications. Due to its broad utility, NHC catalysis has recently demonstrated considerable attention in organic synthesis, materials design, and the late-stage modifications of drugs and natural products. In this review, recent advances (2020-2025) in dual NHC and photoredox catalysis are highlighted, with a particular focus on methodology developments, mechanistic insights, and the reaction scope for the synthesis of ketones, esters, and amide derivatives, including pharmaceutically relevant intermediates. Moreover, this dual catalytic study discusses current synthetic challenges and opportunities for developing more efficient and multicatalytic systems and collecting new mechanistic information under green, sustainable conditions, which tolerate a broad range of functional groups and commercially available, inexpensive, nontoxic starting materials or reagents.