Metal-Free Alkane Functionalization by Organocatalytic and Photoinduced Methods

Transforming alkane C−H bonds into carbon-carbon and carbon-heteroatom bonds represents a paramount objective in synthetic chemistry with significant implications for sustainable production. Although transition-metal catalysts such as Pd, Rh etc have dominated this field, recent breakthroughs in metal-free approaches leveraging small-molecule catalysts or photogenerated intermediates have emerged as efficient and sustainable alternatives. These approaches facilitate precise C−H bond activation and selective formation of C−X (e. g., C, halogen, N, O) bonds under mild conditions, thereby paving a promising avenue for eco-friendly alkane transformations. This review provides an overview of recent advancements in homogeneous metal-free alkane functionalization, focusing on organocatalytic and photoinduced strategies, with the aim of enhancing mechanistic understanding and inspiring the development of innovative synthetic methodologies for the conversion of alkanes into high-value compounds.