Indium(III) trifluoromethanesulfonate: An efficient reusable catalyst for the alkynylation-cyclization of 2-aminoaryl ketones and synthesis of 2,4-disubstituted quinolines

An environmentally friendly and highly efficient procedure for the preparation of 2,4-disubstituted quinoline derivatives has been developed by a simple alkynylation 13cyclization reaction of 2-aminoaryl ketones with phenylacetylenes in the presence of indium( III) trifluoromethanesulfonate In(OTf)3 under microwave irradiation and solvent-free conditions. This catalyst can be recovered after the reaction and reused efficiently in subsequent runs