Chiral oxaziridines in the enantioselective synthesis of isoxazolidines
作者:Luigino Troisi、Sara De Lorenzis、Marilena Fabio、Francesca Rosato、Catia Granito
DOI:10.1016/j.tetasy.2008.09.016
日期:2008.10
The stereoselective synthesis of oxaziridines with three stereogenic centres is presented in this paper. The chirality is provided by asymmetric induction, and a possible mechanism for the induced stereoselectivity is also discussed. These small heterocycles undergo the [3+2] cycloaddition reaction with aryl ethenes to afford enantiomerically pure isoxazolidines of controlled configurations. This class
Diastereoselective addition of Di-(trimethylsilyl)phosphite to chiral N-(R)-α-methylbenzyl and N-(1-methoxycarbonyl-iso-pentyl) Schiff bases of various aldehydes
Novel 3,4-diaryl beta-lactams were prepared with high stereoselectivity in an efficient manner by a palladium-catalyzed [2+2] carborrylative cycloaddition of benzyl halides with heteroarylidene amines. The type of alkyl group linked to the nitrogen atom influences the reaction's stereoselectivity. Moreover, using chiral imines, separable diastereomeric mixtures of chiral 3,4-diaryl-beta-lactams were isolated with good yields and high trans diastereoselections. (C) 2009 Elsevier Ltd. All rights reserved.