Regioselectivity of the addition of Group IVB organometallic radicals to substituted benzo[2,1,3]thiadiazoles. An ESR investigation
作者:Angelo Alberti、Massimo Benaglia、Dea Forentini Dal Monte、Marco Lucarini、Gian Franco Pedulli
DOI:10.1016/0022-328x(91)86190-2
日期:1991.1
Silyl, germyl, stannyl radicals have been reacted with a variety of ring substituted benzo[2,1,3]thiadiazoles, and the paramagnetic adducts resulting from addtion to one of the heterocyclic nitrogens have been characterized by means of ESR spectroscopy. Reactions with unsymmetrically substituted substrates lead to the formation of two distinct isomeric adducts, whose relative amounts depend on the
甲硅烷基,癸基,苯乙烯基已与各种环取代的苯并[2,1,3]噻二唑反应,并且通过ESR光谱对由杂环氮之一加成所产生的顺磁性加合物进行了表征。与不对称取代的底物的反应导致形成两个不同的异构体加合物,其相对量取决于取代基所施加的空间和电子效应。对于在5位带有取代基的化合物,每个单独的异构体加合物的量似乎与其共振稳定程度直接相关。位置4的取代基可分为两类:仅发挥空间效应(Me,Cl)的取代基将附加原子导向受阻较小的氮,而取代基(如MeO)和程度较小的取代基,CN支持更近距离的激进攻击。虽然更多地阻碍了氮。随着温度的升高,有时会观察到两种物质相对稳定性的逆转。