Bismuth(III) salts as synthetic tools in organic transformations

Abstract

Bismuth is the heaviest stable element of the periodic table and even though it carries the status of heavy metal, it is rated as relatively nontoxic and noncarcinogenic unlike its neighboring elements. Additionally, the fact that it tolerates air and moisture makes the chemistry of bismuth attractive to synthetic chemists. The catalytic nature of this metal is attributed to the capability of its salts to acts as Lewis acids in reactions. The nontoxicity together with the ability to endure moisture makes bismuth compounds favorites of chemists and scientists who are concerned about environmental hazards, and such properties are highly desirable for scale-up of a method. The Lewis acidic nature of salts of this element have been thoroughly investigated in various types of reactions such as cycloaddition reactions, reactions of sugars, protection and deprotection reactions, synthesis of heterocyclic systems etc. Since the 1990s, various research groups have successfully utilized this catalytic nature for many organic transformations. Our group's contribution towards the development of methodologies that are useful in accomplishing various functional group manipulations by making use of the catalytic properties of bismuth salts is portrayed here. The mechanistic aspects and the catalytic efficiency of the bismuth(III) salts are accented together with the synthetic utility and the biological and pharmacological applications of the methodologies developed. © 2011 Springer-Verlag Berlin-Heidelberg.