Regioselective Coupling of Different Conjugate Esters by Magnesium Metal Reduction: A Route to Unsymmetrical Adipic Acid Esters.

A novel tactic to synthesize unsymmetrical 3-aryladipic acid esters has been developed via magnesium-promoted reductive coupling of ethyl cinnamates with methyl acrylate. In the present methodology, 3-aryladipic acid derivatives were prepared with good functional group tolerance and a wide substrate scope under very mild reaction conditions in good yields. The application of this reaction to dienic acid esters led to the successful control of the reaction to give 5-aryl-oct-3-enedioic acid esters with high regioselectivity.

Catalyst-Free and Solvent-Controlled Reductive Coupling of Activated Vinyl Triflates with Chlorotrimethylsilane by Magnesium Metal and Its Synthetic Application.

Vinylsilanes were directly prepared from the corresponding vinyl triflates under magnesium-promoted reductive conditions in THF with no transition metal catalyst, and gem-bis-silylated compounds were obtained in NMP. Investigation of the redox potential of starting materials and products suggested that reductive coupling reactions of vinyl triflates might be controlled by the reduction potential. A variety of gem-bis-silylated compounds and 3-silyladipic acid esters were easily synthesized in only two steps from vinyl triflates in high yields.