Triphenylphosphine/germanium(IV) chloride combination:: A new agent for the reduction of α-bromo carboxylic acid derivatives

The Ph3P/GeCl4 combination was found to be effective for the reduction of various alpha-bromo carboxylic acid derivatives. When alpha-bromo carboxylic acid derivatives were treated with Ph3P/GeCl4, the corresponding dehalogenated products were obtained in good to excellent yields. Moreover, selected carboxylic acid derivatives were dehalogenated even when a catalytic amount (0.2 equiv) of GeCl4 was employed in the presence of water (1.0 equiv). The present reduction was also applied to the selective half-reduction of an alpha,alpha-dibromo-beta-lactam.