A silver-catalyzed stereoselective domino cycloisomerization–vinylogous aldol reaction of ortho-alkynylbenzaldehydes with 3-alkylidene oxindoles: an entry to functionalized isochromenes

Abstract

A silver tetrafluoroborate catalyzed domino cycloisomerization–vinylogous aldol addition sequence on a multifunctional substrate such as ortho-alkynylbenzaldehydes yielding functionalized 1H-isochromenes in a single step with high yield and excellent diastereoselectivity (>19 : 1) is described. The reaction was well tolerated by alkyl, aryl, and unsubstituted alkynylbenzaldehydes, and furnished selective 6-endo-dig adducts exclusively without loss in the regio- as well as diastereoselectivity.