The Direct Asymmetric Addition Of 3-Vinyl Indoles With Imines By Acid Catalysis

3-Vinyl indole is one of the most important building blocks for the synthesis of chiral indole compounds. It can be used as dienes, dienophiles for cycloaddition reactions, or electrophiles for Friedel-Crafts-type reactions in asymmetric catalysis. Moreover, 3-vinyl indoles can be used as nucleophiles to synthesize achiral indolyl compound. Using the 3-vinyl indoles as nucleophile, chiral phosphoric acid as catalyst, we managed to produce a series of novel 3-indolyl allylamine compounds with up to 99% yield, and 97% ee, a 99:1 E/Z ratio. This work provided a convenient synthetic route to chiral 3-substituted indole compounds.