H. Ishibashi et al., CONVENIENT SYNTHESIS OF 4-ALKYL, ALKENYL, AND ALKYNYL SUBSTITUTED N-(PHENYLSULFONYL)INDOLES, Chemical and Pharmaceutical Bulletin, 42(10), 1994, pp. 2150-2153
The indolone 1 reacted with organomagnesium or lithium reagents to giv
e the carbinols 6 and 10, which, upon treatment under appropriate acid
ic conditions or neutral thermal conditions, gave the 1-phenylsulfonyl
indoles 8 and 11 bearing various kinds of alkyl, alkenyl, and alkynyl
substituents at the 4-position. The indolone 1 was also converted to t
he 4-cyanoindole 14 via the cyanohydrin O-trimethylsilyl ether 13.