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。