School of Chemistry and University Research Centre in Catalysis and Intensified Processing, Bedson Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK.
J Org Chem. 2010 Sep 17;75(18):6201-7. doi: 10.1021/jo101121h.
The combined use of the bimetallic aluminum(salen) complex Al(salen)O and tetrabutylammonium bromide (or tributylamine) is found to catalyze the reaction between epoxides and carbon disulfide. In most cases, at 50 °C, the reaction produces 1,3-oxathiolane-2-thiones, while at 90 °C, 1,3-dithiolane-2-thiones are the main product. The structure and stereochemistry of three of the 1,3-dithiolane-2-thiones is unambiguously determined by X-ray crystallographic analysis, and this is used to correct errors in the literature concerning the synthesis of cyclic di- and trithiocarbonates. The kinetics of 1,3-oxathiolane-2-thione synthesis are determined, and the resulting rate equation, along with a stereochemical analysis of the reaction and catalyst modification studies, is used to determine a mechanism for the synthesis of 1,3-oxathiolane-2-thiones which contrasts with the mechanism previously determined for cyclic carbonate synthesis using the same bimetallic aluminum(salen) complex.
双金属铝（salen）配合物 [Al(salen)]（2）O 和四丁基溴化铵（或三丁胺）的联合使用被发现可以催化环氧化物和二硫化碳之间的反应。在大多数情况下，在 50°C 下，反应生成 1,3-噁硫杂环戊烷-2-硫酮，而在 90°C 下，主要产物是 1,3-二硫杂环戊烷-2-硫酮。通过 X 射线晶体学分析，明确确定了三个 1,3-二硫杂环戊烷-2-硫酮的结构和立体化学，这用于纠正文献中关于环状二硫代碳酸酯和三硫代碳酸酯合成的错误。确定了 1,3-噁硫杂环戊烷-2-硫酮合成的动力学，并根据所得速率方程、反应的立体化学分析和催化剂修饰研究，确定了一种用于合成 1,3-噁硫杂环戊烷-2-硫酮的机制，该机制与使用相同双金属铝（salen）配合物合成环状碳酸酯的先前确定的机制形成对比。
