Eco-efficient C–H alkynylation of indoles via mechanochemical ruthenium catalysis

Abstract

A regioselective C2-alkynylation of indoles via ruthenium(II)-catalyzed C–H activation using bromoalkynes is demonstrated under both solution-phase and mechanochemical conditions. The solvent-minimized mechanochemical method delivers comparable yields with reduced reaction time and improved green metrics. Broad substrate scope, gram-scale applicability, and post-functionalization showcase the synthetic utility of this approach. This work underscores the potential of mechanochemistry as a sustainable and operationally simple alternative for direct C–H functionalization of heterocycles.