作者:Mariola Calle、Purificación Cuadrado、Ana M. González-Nogal、Raquel Valero
DOI:10.1055/s-2001-17699
日期:——
Silicon or tin 4-metalated pyrazoles and isoxazoles are synthesized by silyl- or stannylcupration from 4-haloazoles. On the other hand, 5-metalated pyrazoles are prepared by reaction of 5-unsubstituted pyrazoles with LDA and subsequent treatment with chlorosilanes and chlorostannanes. Furthermore, starting from 5-unsubstituted 4-halopyrazoles and applying both methodologies, 4,5-dimetalated pyrazoles bearing silyl groups different from trimethylsilyl or tributylstannyl groups are obtained. Some regioselective ipso-substitutions are also studied.
硅或锡4-金属化吡唑和异恶唑是通过硅烷或锡烷锡化作用从4-卤代恶唑合成的。另一方面,5-金属化吡唑是通过5-未取代吡唑与LDA反应,随后用氯硅烷和氯锡烷处理制备的。此外,从5-未取代的4-卤代吡唑出发,并应用这两种方法,得到了具有不同于三甲基硅基或三丁基锡基的不同硅基的4,5-二金属化吡唑。还研究了一些区域选择性原位取代反应。