X=Y-ZH SYSTEMS AS POTENTIAL 1,3-DIPOLES .45. PROTON SPONGE EFFECTS ON THE 1,2-PROTOTROPIC FORMATION OF AZOMETHINE YLIDES FROM ARYLIDENE BENZYLAMINES

被引:14
作者
GRIGG, R [1 ]
MCMEEKIN, P [1 ]
SRIDHARAN, V [1 ]
机构
[1] GLAXO RES & DEV,STEVENAGE SG1 2NY,HERTS,ENGLAND
基金
英国工程与自然科学研究理事会;
关键词
D O I
10.1016/0040-4020(95)00846-Z
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
A strong rate enhancing effect of an ortho-methoxy or an ortho-dimethylamino group on the 1,2-prototropic generation of azomethine ylides from arylidene arylmethylamines is demonstrated. In the absence of such functionality azomethine ylide formation fails to occur in boiling xylene. The reactions generate the E,E- or syn-azomethine ylide stereoselectively if a single ortho- OMe or -NMe(2) group is present or stereospecifically if either bifurcated H-bonding or push-pull stabilisation of the dipole is possible. Cycloadducts with N-phenylmaleimide are obtained in 78-95% yield.
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页码:13331 / 13346
页数:16
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