Ti-triol catalysed trimethylsilylcyanation of acetophenones under high pressure

The first trimethylsilylcyanation of acetophenone to the corresponding (S)-cyanohydrin was accomplished with e.e. up to 60% in 93% yield at 0.8 GPa, using 0.01 eq. of a reusable catalyst prepared from (S)-3,3-dimethyl-1,2,4-butanetriol and titanium isopropoxide. Reactions of 4'-substituted acetophenones to the corresponding cyanohydrins gave lower e.e. and yields.