Heterogeneous Photocatalysis for Late‐Stage Functionalization: A Sustainable Frontier for Complex Molecule Synthesis

Late‐stage functionalization (LSF) enables the direct, site‐selective modification of complex molecules and has become a key strategy in sustainable drug discovery and chemical biology. While homogeneous photocatalysis has traditionally dominated this field, recent advances in materials engineering and catalyst design have triggered a new interest in heterogeneous photocatalysis. Although classical heterogeneous photocatalysts such as metal oxides and carbon nitrides are long established, their nanoscale re‐engineering and integration into LSF have only recently enabled enhanced reactivity, selectivity, and recyclability. This review surveys the recent evolution of heterogeneous photocatalytic systems, from traditional semiconductors to covalent organic frameworks and metal–organic frameworks, for selective LSF. By connecting developments in materials chemistry with photoredox catalysis, this contribution highlights the growing potential of heterogeneous photocatalysts as scalable and sustainable platforms for complex molecule synthesis.