Stereoselective synthesis and characterization of new enantiomerically pure phosphoric acids.
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.
Biaggi
Cinzia
C
Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milano, Italy.
Benaglia
Maurizio
M
Annunziata
Rita
R
Rossi
Sergio
S
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
D003432:Cross-Linking Reagents; D010756:Phosphoric Acids; D002118:Calcium