Synthesis of Six-Membered Carbo-/Heterocycles via Cascade Reaction of Alkynes and Diazo Compounds.

A novel approach toward diverse six-membered carbo-/heterocycles has been developed using diazo compounds and alkyne-substituted malonates as the suitable substrates. The polyfunctionalized cyclohexenes, tetrahydropyridines, and dihydropyrans have been prepared in moderate to high yield under mild reaction conditions. Importantly, the ligand plays a significant role in this copper-catalyzed protocol.