One pot cascade synthesis of fused heterocycles from furan-tethered terminal alkynes and aldehydes in the presence of amines and CuBr

Abstract

A novel one-pot protocol for the construction of complex heterocycles through furan tethered terminal alkynes, aldehydes, amines and CuBr upon heating has been developed, giving the cycloadducts in moderate to high yields along with moderate to good regioselectivities. The reactions proceed through a two-component domino reaction including allenation and subsequent intramolecular Diels–Alder reaction. A wide range of aliphatic or aromatic aldehydes and furan tethered terminal alkynes are well-tolerated, enriching the chemistry of the intramolecular Diels–Alder reaction related to furan.