Water-triggered and gold(I)-catalyzed cascade addition/cyclization of terminal alkynes with ortho-alkynylaryl aidehyde

A highly efficient alkynylation-cyclization of terminal alkynes with ortho-alkynylaryl aldehydes leading to 1-alkynyl-1H-isochromenes was developed by using a gold-phosphine complex as catalyst in water. The reaction was dually promoted by an electron-donating phosphine ligand and water and was chelation-controlled.