Pentavalent organobismuth reagents. Part 3. Phenylation of enols and of enolate and other anions

Abstract

The phenylation of enols and of enolate anions of ketones, β-diketones and keto esters has been studied using a range of Bi reagents. Under basic conditions C-phenylation is observed and, even hindered, perphenylated compounds are easily synthesized. Under neutral and acidic conditions ordinary ketones do not react and enolic systems give O-phenylation. A number of other anions have been phenylated under basic conditions, including the key compound indole which mainly gave 3-C-phenylation. All these reactions can be supposed to have one of two alternative mechanisms, which parallel the two mechanisms proposed for the phenylation of phenols.