Applications of Bismuth Compounds As Catalysts in Organic Synthesis

本项目重点发展铋化合物的新应用，包括利用铋催化剂进行不对称合成。具体目标包括发展二恶氧烷的多组分烯丙化反应，在温和条件下使用碘化铋进行保护-去保护化学，用铋盐催化环加成反应，包括通过Diels Alder反应合成四氢喹啉和吡啶酮，以及开发新的铋盐作为催化剂。在有机和大分子化学项目的支持下，伊利诺伊卫斯理大学化学系的拉姆·莫汉教授正在研究在有机合成中使用铋化合物作为环保催化剂。铋化合物的生物化学、毒理学和环境效应已经有了很好的文献记载。大多数铋化合物是相对无毒的(例如，BiOCl的LD50 （g/kg）为22，Bi2O3的LD50为5；NaCl的LD50为3.75)。铋及其几种化合物在市面上都可以买到，价格相对便宜，而且它们对少量空气和水分不敏感，因此不需要无水溶剂。许多由铋化合物催化的反应也可以在相对无毒的溶剂系统（如丙酮/水）中进行。此外，一些铋化合物的高催化性质使得这些方法适合大规模合成。绿色催化剂的发展应该引起所有执业合成化学家的极大兴趣，特别是对制药加工工业的兴趣。

This project focuses on the development of new applications of bismuth compounds, including asymmetric synthesis using bismuth catalysts. Specific objectives include developing multicomponent allylation reactions of dioxolanes, carrying out protection-deprotection chemistry under mild conditions using bismuth iodide, catalyzing cycloaddition reactions - including the synthesis of tetrahydroquinolines and pyridones via aza Diels Alder reactions - with bismuth salts, and the development of new bismuth salts as catalysts.With the support of this RUI award from the Organic and Macromolecular Chemistry Program, Professor Ram Mohan, of the Department of Chemistry at Illinois Wesleyan University, is studying the use of bismuth compounds as environmentally-friendly catalysts in organic synthesis. The biochemistry, toxicology and environmental effects of bismuth compounds have been well documented. The majority of bismuth compounds are relatively non-toxic (e.g., the LD50 (g/kg) of BiOCl is 22 and that of Bi2O3 is 5; compared with a LD50 of 3.75 for NaCl). Bismuth and several of its compounds are commercially available and are relatively inexpensive, and they are insensitive to small amounts of air and moisture, thus eliminating the need for anhydrous solvents. Many of the reactions catalyzed by bismuth compounds can also be done in relatively non-toxic solvent systems (such as acetone/water). In addition, the highly catalytic nature of several bismuth compounds makes these procedures amenable to large-scale synthesis. The development of green catalysts should be of significant interest to all practicing synthetic chemists and of particular interest to pharmaceutical process industry.