Sulfuration of unreactive C-H bonds

The sulfuration of unreactive carbon-hydrogen bonds stands as one of the significant breakthroughs in organic synthetic chemistry in recent years. This methodology enables the efficient construction of C-S bonds through direct activation of high bond energy C-H bonds, substantially enhancing both synthetic efficiency and atom economy for sulfur-containing compounds. This review systematically summarizes the strategic progress in unreactive C-H bond sulfuration, encompassing core methodologies such as transition-metal catalysis, photocatalytic systems, and electrocatalytic systems. It analyses the sulfur source activation mechanisms under different catalytic modes, the kinetic and thermodynamic driving forces for C-H bond cleavage, and the regulatory principles of site selectivity. Furthermore, it compiles application examples in late-stage sulfuration modification of complex molecules, construction of chiral sulfur centres, and synthesis of bioactive molecules within this field.