An enantioselective tandem Friedel–Crafts alkylation/ Michael addition reaction of 1-methylindoles with nitroolefin enoates catalyzed by a chiral tridentate bisoxazoline-Zn(II) complex has been described. This method provides an efficient route to highly substituted chromans in good isolated yields with high stereoselectivities (up to 95:5 dr and 91% ee).
Key words
tandem reaction - Friedel–Crafts alkylation - 1-methylindole - chroman - nitroolefin enoate