X=Y-ZH systems as potential 1,3-dipoles. Part 32 generation of nitrones from oximes. Tandem Michael addition-1,3-dipolar cycloaddition reactions. Background and class 1 processes.
作者:Ronald Grigg、Frances Heaney、Sivagnanasundram Surendrakumar、William J. Warnock
DOI:10.1016/s0040-4020(01)87116-7
日期:1991.1
keto nitrones can be trapped in regiospecific intermolecular cycloaddition reactions giving single cycloadducts in good yield. Chemospecific 1:1:1 cycloadducts are obtained from ketoximes, monosubstituted electronegative olefins (Michael acceptor) and N-methylmaleimide (dipolarophile), whilst the chemoselectivity of the corresponding reactions with aldoximes is dependent on the oxime stereochemistry.
醛间肟和酮肟的分子间迈克尔加成反应生成负电烯烃。酮硝酮可被困在区域特异性的分子间环加成反应中,从而以高收率得到单个环加合物。从酮肟,单取代的负电烯烃(Michael受体)和N-甲基马来酰亚胺(双极亲和性)获得化学特异性的1:1:1环加合物,而与醛肟的相应反应的化学选择性取决于肟的立体化学。Z-醛固酮显示出高的化学特异性,而E-醛肟则具有较低的化学选择性。