INDOL-2-YLTRIBUTYLSTANNANE - A VERSATILE REAGENT FOR 2-SUBSTITUTED INDOLES

A general method for 2-substituted indoles via the palladium-catalyzed coupling of indol-2-ylstannanes is described. (N-Methylindol-2-yl)tri butylstannane (1) reacts with a variety of electrophiles under very mi ld conditions: [N-tert-Butoxycarbonyl)indol-2-yl]tributylstannane (3) is much less reactive in the coupling reactions and reacts only with c ertain activated electrophiles. thylsilyl)ethoxy]methylindol-2-yl]trib utylstannane (4) behaves similarly to 1 and the removal of the [(trime thylsilyl)ethoxy]methyl group can be achieved with tetra-n-butylammoni um fluoride in DMF in the presence of ethylenediamine.