The experimental and computational study of the mechanism of the iminium‐organocatalyzed formation of N‐hydroxypyrrolidines from nitrones, revealed up to three activation levels of the Schreiner's thiourea used as co‐catalyst, i.e: (i) formation of the iminium ion through hydroxyl anion recognition forming a stable ion pair; (ii) enolization of the nitrone through a H‐bond network and (iii) activation of the nitrone moiety towards the final ring closure. The computational model supports the mechanism and the catalytic cycle. This mechanistic rationale is supported by the lack of reactivity of preformed iminium ion with the nitrone in the absence of thiourea‐hydroxyl complex and the observed reactivity when a complex thiourea‐tetrabutylammonium hydroxide is added.

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羟基阴离子结合硫脲辅助的铟形成的案例研究：动力学，光谱和计算证据

实验和计算研究的亚硝胺由亚硝基有机催化形成N-羟基吡咯烷的机理揭示了高达三个激活水平的Schreiner硫脲用作助催化剂，即：（i）通过羟基阴离子形成亚胺离子识别形成稳定的离子对；（ii）通过H键网络将硝酮烯醇化（iii）朝最终的闭环活化硝酮部分。该计算模型支持机理和催化循环。在没有硫脲-羟基络合物的情况下，预制的亚胺离子与硝酮缺乏反应性，以及添加氢氧化硫脲-四丁基铵络合物时观察到的反应性，支持了这种机理原理。