SYNTHESIS OF 2,3-DISUBSTITUTED INDOLES BY ALKYLATIVE AND ARYLATIVE CYCLIZATION OF 2-ALKENYLPHENYLISOCYANIDES WITH GRIGNARD REAGENTS

Alkylative cyclization of 3-(2-isocyanophenyl)propenoic acid tent-butyl ester with Grignard reagents proceeds smoothly to form 2-alkyl-indole-3-acetic acid derivatives in moderate-to-good yields. Substituted 3-(2-isocyanophenyl)propenoic acid tert-butyl esters undergo a similar reaction when phenylmagnesium bromide is used to render 2-phenylindole-3-acetic acid derivatives in moderate-to-good yields.