Enantioselective nitromethane addition to brominated and fluorinated benzaldehydes (Henry reaction) catalyzed by chiral bisoxazoline–copper(II) complexes
The successful enantioselective Henry reaction of nitromethane to brominated and fluorinated benzaldehydes was achieved using a chiral bisoxazoline (unbridged)-Cu(II) complex as a catalyst. Nitroalcohols were obtained in excellent yields (up to 99%) and with enantioselectivities up to >99%. Theoretical calculations support the idea that the unbridged bisoxazoline-Cu(II) complex behaves similarly to the privileged bisoxazolines as catalysts in the Henry reaction. (C) 2016 Elsevier Ltd. All rights reserved.