1,4-Asymmetric Induction in Methoxyselenenylation of Double Bonds at the Nitrogen Side of Chiral Perhydro-1,3-benzoxazines Promoted by Nonbonded Se···N Interactions
cinnamylamines attached to a chiral perhydrobenzoxazine occurs in high yields by reaction with benzeneselenenyl chloride in dichloromethane−methanol. The diastereoselection is dependent on the temperature of the reaction and the structure of the substituent at C-2 and can be rationalized by accepting a 1,4-asymmetricinduction process after coordination of the selenium to the nitrogen atom of the allylamine
Diastereoselective Yang Photocyclization Reactions in Solution. Synthesis of Enantiopure Azetidin-3-ol Derivatives
作者:Rafael Pedrosa、Celia Andrés、Javier Nieto、Soledad del Pozo
DOI:10.1021/jo0481497
日期:2005.2.1
Chiral 2-acyl-3-allyl- or 2-acyl-3-benzyl-substituted perhydro-1,3-benzoxazines readily cyclized under irradiation to azetidin-3-ol derivatives. The diastereoselectivity of the cyclization is dependent on the nature of the substituents at the nitrogen atom. N-allyl-substituted derivatives yielded only two of the four possible diastereomers in moderate to good diastereomeric excess. The cyclization