Preparation and diastereo- and enantioselective trifluorocrotylboration with (Z)-(B)-diisopinocampheyl(4,4,4-trifluorobut-2-en-1-yl)borane

Contrary to the non-fluorinated analogs, the hydroboration of trifluoromethylallene with diisopinocampheylborane provides the corresponding Z-trifluorocrotylborane reagent. Trifluorocrotylboration of a series of aldehydes with this reagent provides the corresponding syn-β-trifluoromethyl homoallyl alcohols in high diastereo- and enantioselectivities.