Resolution and Stereochemistry of tert-Butylphenylphosphinous Acid−Borane

• Published in: Journal of organic chemistry Vol. 72; no. 3; pp. 816 - 822
• Main Authors: Stankevič, Marek, Pietrusiewicz, K. Michał
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 02.02.2007; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; CATALYZED ASYMMETRIC HYDROGENATION; KETONES; DIPHOSPHINE LIGANDS; OXIDE; REDUCTION; CHIRAL PHOSPHINE-LIGANDS; ENANTIOMERS; COMPLEXES; CHEMISTRY; Organic phosphinite; Tertiary phosphine; Nitrogen heterocycle; Secondary phosphine; Ephedrine; Organic anhydride; Stereochemistry; Organic halogen compounds; Phosphorus Organic compounds; Stereoselectivity; Racemic; Alkaloid; Phosphine borane; Organic borane; Chemical synthesis; Enantiomer(-)
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo061896e

A combined use of ephedrine and cinchonine as resolving agents enabled facile resolution of racemic tert-butylphenylphosphinous acid−borane (1) into the two enantiomers in ca. 31−32% yield each. The resolved 1 served as a model substrate to study stereoselective synthetic transformations of phosphinous acid−boranes yielding optically active phosphinite−borane, boranatophosphinous−sulfonic anhydride, secondary phosphine−borane, tertiary phosphine−borane, secondary phosphine oxide, and phosphinic halides. By the judicious choice of the reaction paths, either enantiomer of tert-butylphenylphosphine−borane and of tert-butylmethylphenylphosphine−borane could be stereoselectively obtained from a single enantiomer of 1.