Visible Light-Driven Manganese Photocatalysis for Sustainable Organic Synthesis

Manganese-based photocatalysis has emerged as a sustainable strategy in modern organic synthesis, leveraging manganese's natural abundance, low toxicity, versatile redox behavior, and tunable coordination environments. This review classifies manganese photocatalysts into three main structural categories: (i) dinuclear Mn₂(CO)₁₀, (ii) mononuclear complexes with simple ligands (including manganese salts), and (iii) well-defined complexes supported by elaborate ligand frameworks. The article systematically summarizes their applications in a range of photocatalytic transformations, such as C─H functionalization, alkene modification, coupling reactions, and redox processes, along with relevant mechanistic insights and structure-activity relationships. While challenges remain in catalyst stability, structural diversity, and stereocontrol, manganese-based photocatalysis shows strong potential for enabling greener and more sustainable synthetic routes. By providing a clear, categorization-based overview, this review aims to encourage further developments in this rapidly evolving field.