A Csp3–Csp3 Bond Forming Reductive Condensation of α-Keto Esters and Enolizable Carbon Pronucleophiles

The preparation of densely functionalized unsymmetrical 1,4-dicarbonyl structural motifs by a phosphorus(III)-mediated reductive condensation of α-keto esters and enolizable carbon pronucleophiles is described. The reaction, which is initiated by Kukhtin-Ramirez addition of commercially available tris(dimethylamino)phosphine to the α-keto ester substrate, proceeds rapidly under mild conditions.