Efficient synthesis of 3-substituted indoles through a domino gold(I) chloride catalyzed cycloisomerization/C3-functionalization of 2-(alkynyl)anilines

An efficient synthesis of 3-substituted indoles by a sequential approach involving gold(I) chloride catalyzed cycloisomerization/bis-addition and conjugate addition of 2-(alkynyl)anilines has been accomplished. A variety of 2-(alkynyl)anilines, aldehydes, isatins and nitroolefins undergo this overall process in good to excellent yields. This methodology represents an effective alternative to the classical C3-functionalization of indoles.