George J. Quallich

Enantioselective oxazaborolidine reduction of ketones containing heteroatoms

Abstract Ketones which contain heteroatoms, particularly nitrogen, can be enantioselectively and catalytically reduced with chiral oxazaborolidines in the presence of excess borane.

Diphenyloxazaborolidine a new catalyst for enantioselective reduction of ketones

Abstract A variety of ketones can be reduced in high enantioselectivity with the oxazaborolidines derived from commercially available erythro aminodiphenylethanol.

Synthesis of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone by SN2 cuprate displacement of an activated chiral benzylic alcohol

Abstract Two routes for the preparation of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone are reported. The most efficient route generates a chiral benzylic alcohol by catalytic asymmetric oxazaborolidine reduction of a γ-ketoester that is subsequently activated and displaced in an SN2 manner with a higher order cuprate. Intramolecular Friedel-Crafts cyclization of the resulting t-butylester affords the title compound.

Enantioselective synthesis of C2-symmetric diols

Catalytic reduction of diketones with erythro diphenyl oxazaborolidine yielded C2-symmetric diols in high enantiomeric excess. Enantiomeric excess increased and less meso isomer was generated when borane was employed equimolar with respect to the carbonyl groups and when stoichiometric oxazaborolidine was used.

Diastereoselective oxidation of sulfides to sulfoxides with potassium peroxymonosulfate

Abstract Potassium peroxymonosulfate oxidation of sulfides to sulfoxides occurs with high diastereoselectivity.