Divergent Palladium‐Catalyzed Cross‐Coupling of Nitropyrazoles with Terminal Alkynes

Abstract

Facile homo‐coupling of terminal alkynes, which generates conjugated diynes, is an undesired pathway in the development of transition‐metal‐catalyzed oxidative C–H functionalization of (hetero)arenes with terminal alkynes. By incorporating this process into a catalytic cycle, we achieved regio‐ and stereoselective hydroarylation of nitropyrazoles with the resulting 1,3‐diynes. A simple change in the stoichiometry and oxidant allowed direct C–H alkynylation of nitropyrazoles, producing the corresponding alkynyl pyrazoles.