Asymmetric reduction of prochiral aromatic ketones by Borane–Amine complexes in the presence of a chiral amine–BF3 catalyst
Abstract
The (–)-N-α-Methylbenzyl-3,5-dihydrodinaphthazepine–BH3 complex reduces aromatic ketones to alcohols with 11–57% enantiomeric excess (e.e.) in the presence of BF3·OEt2, the (–)-N-α-methylbenzyl-3,5 dihydrodinaphthazepine–BF3 complex catalyses asymmetric reduction of acetophenone by N,N′-diethylaniline–BH3 to give α-phenylethyl alcohol in 51% e.e.