作者:M. Franck-Neumann、C. Dietrich-Buchecker
DOI:10.1016/0040-4020(78)88422-1
日期:1978.1
3-dimethyl-3H-pyrazoles in unsaturated solvents leads in good yields and often with high stereoselectivity, to vinylcarbene cycloadducts. This direct synthesis of vinylcyclopropanes, vinylcyclopropenes and divinylcyclopropanes shows that acyclic vinyl carbenes are not necessarily intramolecularly stabilized. They can actually be trapped by olefins, acetylenes or dienes, depending on the carbene substituents. Cyano
3,3-二甲基-3H-吡唑类化合物在不饱和溶剂中的光解可产生良好的收率,并且通常具有很高的立体选择性,从而可生成乙烯基碳烯环加合物。乙烯基环丙烷,乙烯基环丙烯和二乙烯基环丙烷的这种直接合成表明,无环乙烯基卡宾不一定是分子内稳定的。实际上,取决于卡宾取代基,它们实际上可能被烯烃,乙炔或二烯捕获。到目前为止,氰基乙烯基碳烯是最有效的分子间环附加物,但是烷氧基甚至酮乙烯基碳烯都可以与二烯发生环丙烷化反应,在最后一种情况下,与沃尔夫重排的竞争很小。