Non-Dipolar Behavior of Mesoionic Heterocycles: Synthesis and Tautomerism of 2-Alkylthioisomünchnones
作者:Martín Ávalos、Reyes Babiano、Pedro Cintas、Jesús Díaz、José L. Jiménez、Ignacio López、Juan C. Palacios
DOI:10.1002/ejoc.200400049
日期:2004.7
of 1,3-thiazolium-4-olates, each bearing an alkyl group at C-2, through reactions between N-arylthiocarboxamides and α-haloacyl halides. Unlike the 2-aryl-substituted derivatives, such alkylated mesoionic compounds exist in equilibria with their non-dipolar tautomers, the corresponding 2-alkylidene-1,3-thiazolidin-4-ones. The unambiguous characterization of such tautomers and their relative stabilities
本文描述了一系列 1,3-thiazolium-4-olates 的一般制备,每个 1,3-thiazolium-4-olates 在 C-2 处带有一个烷基,通过 N-芳硫基甲酰胺和 α-卤代酰卤之间的反应。与 2-芳基取代的衍生物不同,此类烷基化介离子化合物与其非偶极互变异构体(相应的 2-亚烷基-1,3-噻唑烷-4-酮)平衡存在。这种互变异构体的明确表征及其相对稳定性现已通过光谱和计算研究进行评估。杂环 N-3 处 o,o'-二取代芳基的存在减慢了围绕 N-Ar 键的自由旋转,从而开辟了一类有前途的非联芳阻转异构体。最后,用α-卤代酰基卤化物处理N-芳基硫代甲酰胺产生N-酰基硫代甲酰胺而不是相应的介离子物质。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)