For reviews of oxazaborolidines as enantioselective catalysts, see: Angew. Chem. Int. Ed., 31, 729 (1992); 37, 1986 (1998); Tetrahedron: Asymmetry, 3, 1475 (1992).
Catalyst for the CBS (Corey, Bakshi, Shibata) reduction of prochiral ketones with borane-THF, with high enantioselectivity (see (S)-(-)-ɑ,ɑ-Diphenylprolinol, L09217): J. Am . Chem. Soc., 109, 7925 (1987):
For successful use of this system in a scaled up asymmetric synthesis of the antiarrythmia agent d-Sotalol, see: Org. Process Res. Dev., 1. 176 (1997). For use in enantioselective reduction of ketones containing heteroatoms, see: Tetrahedron Lett., 34, 785 (1993). For the asymmetric reduction of ɑ-ketoimines, see: Tetrahedron Lett., 35, 5551 (1994).
Air-stable solid prepared by a modification of Corey's procedure, on which his literature results were based. For anhydrous reagent, see (S)-2-Methyl-CBS-oxazaborolidine, L14583.
For reviews of the asymmetric reduction of ketones, see: Synthesis, 605 (1992); Chem. Ind. (London), 552 (1994).
Anhydrous catalyst for 'CBS' reduction reaction. For examples of use in asymmetric reduction of ketones, see: Org. Synth. Coll., 9, 362, 676 (1998). For further information, see (S)-2-Methyl-CBS-oxazaborolidine monohydrate, L09219.