Imidazol-2-and-4-ylidene by decarboxylation. Studies on the cross-conjugated mesomeric betaine-alkaloid norzooanemonine and its pseudo-cross-conjugated isomer
作者:Andreas Schmidt、Ariane Beutler、Marcel Albrecht、Bohdan Snovydovych、Francisco Javier Ramírez
DOI:10.1039/b716508k
日期:——
1,3-Dimethylimidazolium-2-carboxylate and -4-carboxylate (norzooanemonine), which belong to two distinct classes of heterocyclic mesomeric betaines, undergo thermal decarboxylations to the N-heterocyclic carbenes imidazol-2-ylidene and imidazol-4-ylidene, respectively. These carbenes can be detected by ESI mass spectrometry and can be trapped by isocyanates to imidazolium-amidates, the structure of
属于两类不同的杂环美苏木甜菜碱的1,3-二甲基咪唑-2-羧酸盐和-4-羧酸盐(去甲鸟氨酸)经历热脱羧作用,形成N-杂环卡宾咪唑-2-亚基和咪唑-4-亚基,分别。这些碳烯可以通过ESI质谱检测,并且可以被异氰酸酯捕获为氨基咪唑鎓,其结构通过独立的合成方法得到了证明。我们进行了计算以表征咪唑羧酸盐的不同共轭类型。