Synthesis of naphthalene amino esters and arylnaphthalene lactone lignans through tandem reactions of 2-alkynylbenzonitriles.

Tandem reaction of 2-alkynylbenzonitriles with a Reformatsky reagent turned out to be a novel and efficient approach toward 1-aminonaphthalene-2-carboxylates. Interestingly, with 2-(3-hydroxyprop-1-ynyl)benzonitriles as the substrates, a more sophisticated cascade process occurred to give 9-aminonaphtho[2,3-c]furan-1(3H)-ones in good yields. By using this tandem reaction as a key step, a concise and versatile synthetic strategy for the total synthesis of arylnaphthalene lactone lignans has been developed.