Pentavalent organobismuth reagents in organic synthesis: Alkylation, alcohol oxidation and cationic photopolymerization

Abstract

Organic transformations using organobismuth(V) reagents developed by my group are reviewed. The characteristic properties of bismuth, such as the inert pair effect, small bond dissociation energy, and polarized bonding are strongly related to the reactivity of pentavalent organobismuth compounds. The Bi(V) reagents discussed in this chapter include tetraorganylbismuthonium salts ([Ar 3RBi +][X -]), triarylbismuth ylides (Ar 3Bi=CHCOR), triarylbismuth imides (Ar 3Bi=NCOR), triarylbismuth oxides (Ar 3Bi=O), and triarylbismuth dichlorides (Ar 3BiCl 2). These organobismuth(V) compounds are readily accessible in a few steps from triarylbismuthanes (Ar 3Bi). New and efficient carbon-carbon bond forming reactions, carbon-heteroatom bond forming reactions, alcohol oxidation, and photoinduced cationic polymerization have been investigated using these reagents. In all these reactions, the good leaving ability as well as the high nucleofugality of the triarylbismuthonio group plays a crucial role in bond-forming and bond-breaking steps. © 2011 Springer-Verlag Berlin Heidelberg.