Heterocycle Syntheses with Anionic N-Heterocyclic Carbenes: Ring Transformations of Sydnone Imine Anions
作者:Tyll Freese、Ana-Luiza Lücke、Jan C. Namyslo、Martin Nieger、Andreas Schmidt
DOI:10.1002/ejoc.201800028
日期:2018.4.17
Sydnone imine anions combine elements of anionic N‐heterocyclic carbenes and mesomeric betaines. Thus, reaction with isocyanates (X=O) or isothiocyanates (X = S) give adducts of the carbene‐type σ orbitals, whereas ring transformations to give imidazolidine‐2,4‐dithiones, imidazolin‐2,4‐diones and 1,2,4‐triazol‐5‐ons result from the characteristic π‐architecture of betaines.
Sydnone亚胺阴离子结合了阴离子N-杂环卡宾和Mesomeric甜菜碱的元素。因此,与异氰酸酯(X = O)或异硫氰酸酯(X = S)反应生成卡宾型σ轨道的加合物,而环转化生成咪唑烷-2,4-二硫酮,咪唑啉-2,4-二酮和1, 2,4-三唑-5-on是甜菜碱的独特π结构。