Calvet, Geraldine and Coote, Susannah C. and Blanchard, Nicolas and Kouklovsky, Cyrille (2010) alpha-Acyloxynitroso dienophiles in [4+2] hetero Diels-Alder cycloadditions : mechanistic insights. Tetrahedron, 66 (16). pp. 2969-2980. ISSN 0040-4020
Full text not available from this repository.Abstract
alpha-Acyloxynitroso derivatives are a class of heterodienophiles leading to valuable 3,6-dihydro-1,2-oxazines or the corresponding aminoalcohols in good yields. The discovery that a beta-oxygenated moiety led to a domino [4+2] cycloaddition/sigma(N-O) bond cleavage in the presence of a catalytic amount of Lewis acid was investigated in detail, through kinetic profiling of the reaction both in the absence and presence of a promoter. These studies showed that the role of the Lewis acid was to accelerate the sigma(N-O) bond cleavage thereby promoting a highly reproducible sequence. In addition, our preliminary results on an asymmetric version of this domino sequence are reported. (C) 2010 Elsevier Ltd. All rights reserved.