Abstract: | In the present paper, the ab initio molecular orbital method is employed to study the structures of the adducts of borane and aromatic ketone to chiral cyclic sulfur‐containing oxazaborolidine used as a catalyst in the enantioselective reduction of aromatic ketone. The catalyst–borane–ketone adducts have four different structures. All the structures are optimized completely by means of the Hartree–Fock method at 6‐31g* basis sets. The structure which is of the greatest advantage to a hydride transfer from the borane moiety to the carbonyl carbon of aromatic ketone is the one with the next lowest formation energy, and the plausible transition state for the hydride transfer is predicted to be of a twisted boat structure. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 252–260, 2000 |