The one-pot reaction of chlorosulfonyl isocyanate (CSI) with epoxides having phenyl, benzyl and fused cyclic alkyl groups in different solvents under mild reaction conditions without additives and catalysts was studied. Oxazolidinones and five-membered cyclic carbonates were obtained in ratios close to 1:1 in the cyclization reactions. The best yields of these compounds were obtained in dichloromethane (DCM). Together with 16 known compounds, two novel oxazolidinone derivatives and two novel cyclic carbonates were synthesized with an efficient and straightforward method. Compared to the existing methods, the synthetic approach presented here provides the following distinct advantageous: being a one-pot reaction with metal-free reagent, having shorter reaction times, good yields and a very simple purification method. Moreover, using the density functional theory (DFT) method at the M06-2X/6-31+G(d,p) level of theory the mechanism of the cycloaddition reactions has been elucidated. The further investigation of the potential energy surfaces associated with two possible channels leading to oxazolidinones and five-membered cyclic carbonates disclosed that the cycloaddition reaction proceeds via an asynchronous concerted mechanism in gas phase and in DCM.

中文翻译：

---

一锅法从环氧化物和氯磺酰基异氰酸酯合成恶唑烷酮和五元环状碳酸酯：异步协同途径的理论证据。

在没有添加剂和催化剂的温和反应条件下，研究了氯磺酰基异氰酸酯（CSI）与具有苯基，苄基和稠环烷基的环氧化物在不同溶剂中的一锅反应。在环化反应中，恶唑烷酮和五元环状碳酸酯的比例接近1：1。这些化合物在二氯甲烷（DCM）中的收率最高。与16种已知化合物一起，用一种有效而直接的方法合成了两种新型的恶唑烷酮衍生物和两种新型的环状碳酸酯。与现有方法相比，此处提出的合成方法具有以下明显的优势：与不含金属的试剂进行一锅法反应，反应时间短，收率高，纯化方法非常简单。此外，在M06-2X / 6-31 + G（d，p）的理论水平上使用密度泛函理论（DFT）方法，阐明了环加成反应的机理。对与导致恶唑烷酮和五元环状碳酸酯的两个可能通道相关的势能面的进一步研究显示，环加成反应通过气相和DCM中的异步协同机制进行。