Vicinal elimination of trimethylsilyl and benzotriazolyl groups from 2-benzotriazolyl-2-aryl-3-ketopropylsilanes forms, along with the expected 1,1-disubstituted ethylenes, significant amounts of the corresponding chalcones. A study of this transformation by carbon labeling suggests the intermediate formation of cyclopropanes. Stabilizing/destabilizing (electron-donor/acceptor) para-substituents on the aryl group affect the product distribution of the elimination in a manner consistent with the proposed mechanism.
2-
苯并三唑基-2-芳基-3-
酮丙基
硅烷中的三
甲基硅烷基和
苯并三唑基发生堇青基消除反应,与预期的 1,1-二取代
乙烯一起形成大量相应的
查耳酮。通过
碳标记对这种转化的研究表明,中间会形成
环丙烷。芳基上的稳定/不稳定(电子供体/受体)对位取代基会影响消除反应的产物分布,其方式与所提出的机理一致。