Switchable Cycloadditions of Mesoionic Dipoles: Refreshing up a Regioselective Approach to Two Distinctive Heterocycles
作者:M. Pilar Romero-Fernández、Pedro Cintas、Sergio Rojas-Buzo
DOI:10.1021/acs.joc.2c01444
日期:2022.10.7
Mesoionic rings are among the most versatile 1,3-dipoles, as witnessed recently by their incorporation into bio-orthogonal strategies, and capable of affording unconventional heterocycles beyond the expected scope of Huisgen cycloadditions. Herein, we revisit in detail the reactivity of thiazol-3-ium-4-olates with alkynes, leading to thiophene and/or pyrid-2-one derivatives. A structural variation
介离子环是用途最广泛的 1,3-偶极子之一,正如最近通过将它们纳入生物正交策略所证明的那样,并且能够提供超出预期范围的 Huisgen 环加成的非常规杂环。在此,我们详细回顾了 thiazol-3-ium-4-olates 与炔烃的反应性,从而产生噻吩和/或 pyrid-2-one 衍生物。母体介离子偶极子的结构变化充分改变了空间结果,从而有利于区域选择性形成单个瞬态环加合物,该环加合物经历化学选择性断裂成五元或六元杂环。合成协议主要受益于微波 (MW) 激活,从而提高了反应速率。借助密度泛函理论 (DFT) 计算对该机制进行了研究,