The asymmetric catalytic aldol reaction of allenolates with aldehydes using N-fluoroacyl oxazaborolidine as the catalyst

[GRAPHICS] The asymmetric catalytic aldol reaction of silyl allenolates with aldehydes has been achieved by using N-C3F7CO oxazaborolidine as the catalyst. The f luoroacyl group of the catalyst was found to be crucial for control of enan tioselectivity. The reaction provides the first enantioselective approach t o beta -halo Baylis-Hillman-type adducts.