title: Stereoselective synthesis and characterization of new enantiomerically pure phosphoric acids.
abstract: Starting from (R)-6,6'-dimethyldiphenyl-2,2'-dicarboxylic acid, a novel class of enantiomerically pure cyclic dialkyl phosphates was synthesized and properly characterized. The absolute configuration was determined by 2D NOESY experiments. The catalytic behavior of the new chiral Bronsted acids was investigated in the stereoselective addition of a silyl keteneacetal to aldimines. The Mannich-type reaction was promoted in up to 94% yields and enantioselectivities up to 55%. On the basis of preliminary molecular mechanic calculations, a model of stereoselection was also proposed to explain the sense of the enantioselectivity observed in the reaction.
authors: Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milano, Italy.
authors: Cinzia
authors: C
authors: Biaggi
authors: Maurizio
authors: M
authors: Benaglia
authors: Rita
authors: R
authors: Annunziata
authors: Sergio
authors: S
authors: Rossi
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D006801:Humans; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010756:Phosphoric Acids / Q000138:chemical synthesis* / Q000737:chemistry; D011487:Protein Conformation; D013237:Stereoisomerism
chemical_list: D003432:Cross-Linking Reagents; D010756:Phosphoric Acids; D002118:Calcium