Direct, catalytic enantioselective nitroaldol (Henry) reaction of trifluoromethyl ketones:: An asymmetric entry to α-trifluoromethyl-substituted quaternary carbons

Herein we describe the first direct, catalytic enantioselective nitroaldol (Henry) reaction of simple alpha-trifluoromethyl ketones with nitromethane using a chiral monometallic lanthanum(III) triflate salt complex, namely [(Delta,S,SS)-Binolam](3 center dot)La(OTf)(3), as enantioselective catalyst. The resulting alpha-trifluoromethyl tertiary nitroaldols were obtained in moderate to high yields (up to 3%) and enantioselectivities (up to 98% ee). These adducts are versatile chiral building blocks and may be reduced (NiCI2/NaBH4) to their beta-amino-alpha-trifluoromethyl tertiary alcohols without loss of enantiomeric purity.