Cycloaddition of New N -Unsubstituted Azomethine Ylides Generated from N -(Trimethylsilylmethyl)thioureas to Electron-Deficient Olefins, Acetylenes and Aldehydes, Synthetic Equivalents of Nonstabilized Aminonitrile Ylides 1
作者:Otohiko Tsuge、Taizo Hatta、Hideki Tashiro、Yoshikazu Kakura、Hironori Maeda、Akikazu Kakehi
DOI:10.1016/s0040-4020(00)00688-8
日期:2000.9
The S-methylation of N-(trimethylsilylmethyl)thioureas and the subsequent desilylation of the silylmethyl group generates N-unsubstituted azomethine ylides having both methylthio and amino groups at the ylide carbon. These azomethine ylides undergo successful cycloaddition to electron-deficient olefins, acetylenes and aldehydes. As the methylthio group is eliminated under the reaction conditions to
N-(三甲基甲
硅烷基甲基)
硫脲的S-甲基化和随后的甲
硅烷基甲基的甲
硅烷基化产生在叶立德碳上同时具有甲
硫基和
氨基的N-未取代的甲
亚胺基化物。这些偶氮次甲基可成功地与电子不足的烯烃,
乙炔和醛进行环加成反应。由于在反应条件下消除了甲
硫基以产生相应的在2-位带有
氨基的
吡咯啉,
吡咯和2-
恶唑啉,因此这些偶氮甲碱可为非稳定的
氨基腈的合成等价物,否则它们是相对难以获得的。