engleski

Lipase-catalyzed acetylation of 3-substituted 2, 3-dihydro-1H-1, 4-benzodiazepin-2-ones : effect of temperature and conformation on enantioselectivity and configuration

Enantioselectivty of acetylation by vinyl acetate/AcOEt catalyzed by immobilized Candida antarctica lipase (Novozym 435) is studied for rac-3-(hydroxymethyl)-1, 4-benzodiazepin-2-ones 7, 9, 14 and for prochiral 3, 3-bis(hydroxymethyl) derivative 16. Enantiomeric excess is correlated with conformational properties of substrates as determined by DNMR and MM2 calculations. For racemic alcohols 7, 9, 14 and 20, preferred acetylation of the (3S)-enantiomers, present in solution in absolute (M)-conformation, was established ; only in prochiral diol 16 the CH2OH group in the (pro-R)-position is prevalently acetylated, presumably due to the binding to the enzyme, in absolute (P)-conformation.

human-serum albumin; alpha-amino-acids; chiral 1; 4-benzodiazepin-2-ones; kinetic resolutions

nije evidentirano