Applications of Bismuth Compounds As Catalysts in Organic Synthesis

该项目的重点是开发铋化合物的新应用，包括使用铋催化剂的不对称合成。具体目标包括开发二氧戊环的多组分烯丙基化反应，使用碘化铋在温和条件下进行保护-脱保护化学，用铋盐催化环加成反应-包括通过氮杂Diels桤木反应合成四氢喹啉和吡啶酮-以及开发新的铋盐催化剂。伊利诺伊州卫斯理大学化学系的拉姆·莫汉教授正在研究铋化合物在有机合成中作为环境友好催化剂的用途。铋化合物的生物化学、毒理学和环境效应已被充分记录。大多数铋化合物是相对无毒的（例如，BiOCl的LD 50（g/kg）为22，Bi 2 O3的LD 50（g/kg）为5;而NaCl的LD 50为3.75）。铋和它的几种化合物是可商购的并且相对便宜，并且它们对少量空气和水分不敏感，从而消除了对无水溶剂的需要。许多由铋化合物催化的反应也可以在相对无毒的溶剂体系（如丙酮/水）中进行。此外，几种铋化合物的高催化性质使得这些程序适合于大规模合成。绿色催化剂的开发是合成化学家和制药工业特别关注的问题。

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.