A Practical Process for the Preparation of Tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolooxazaborole-Borane. A Highly Enantioselective Stoichiometric and Catalytic Reducing Agent

Article abstract of DOI:10.1021/jo00062a037

A practical, large-scale process for the preparation of tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo<1,2-c><1,3,2>oxazaborole-borane is reported.The title compound is a stable, free-flowing crystalline solid useful either stoichiometrically or catalytically for the enantioselective reduction of prochiral ketones.When used stoichiometrically to reduce acetophenone the enantioselectivity is >= 99.8 percent ee.