Au-catalyzed cascade addition/cyclization/H-transfer reactions of 3-(1-alkynyl)chromones to construct 4H-Furo[3,2-c]pyrans scaffold

Using Au catalyst and ethyl Hantzsch ester as a hydrogen source, 3-(1-alkynyl)chromones were directly transformed to 4H-benzofuro[3,2-c]pyrans in good to excellent yields through a cascade process by addition, cyclization and hydrogen transfer under mild conditions.