LiAl(OC(Ph)(CF₃)₂)₄:  A Hydrocarbon-Soluble Catalyst for Carbon−Carbon Bond-Forming Reactions

The compound LiAl(OC(Ph)(CF3)2)4 (1), prepared from LiAlH4 and HOC(Ph)(CF3)2, is an active Lewis acid catalyst in toluene solution for the 1,4-conjugate addition of silyl ketene acetals to α,β-unsaturated carbonyl compounds and for the direct substitution of allylic acetates by silyl ketene acetals. The structure of 1 contains a rare trigonal prismatic coordination sphere around the Li+ cation, with two Li−O(C, Al) bonds and four Li−F(C) bonds.