QUANTUM-CHEMICAL MODELING OF CHIRAL CATALYSIS .15. ON THE ROLE OF HYDRIDE-BRIDGED BORANE-ALKOXYBORANE COMPLEXES IN THE CATALYTIC ENANTIOSELECTIVE REDUCTION OF KETONES PROMOTED BY CHIRAL OXAZABOROLIDINES
V. Nevalainen, QUANTUM-CHEMICAL MODELING OF CHIRAL CATALYSIS .15. ON THE ROLE OF HYDRIDE-BRIDGED BORANE-ALKOXYBORANE COMPLEXES IN THE CATALYTIC ENANTIOSELECTIVE REDUCTION OF KETONES PROMOTED BY CHIRAL OXAZABOROLIDINES, Tetrahedron : asymmetry, 5(2), 1994, pp. 289-296
Hydride-bridged borane - alkoxyborane complexes of oxazaborolidines we
re investigated by means of ab initio molecular orbital methods (RHF).
The complexes wire found to be stable in the absence of Lewis basic s
olvents. In the presence of a Lewis basic solvent the borane - alkoxyb
orane complexes were predicted to decompose leading to the formation o
f borane - solvent complexes of the oxazaborolidines. A new class of o
xazaborolidine catalysts, of which the mechanism of regeneration would
be based on borane - borane hydride exchange, was invented.