Sulfoxide-Modified Julia-Lythgoe Olefination: Highly Stereoselective Di-, Tri-, and Tetrasubstituted Double Bond Formation

A novel modification of the classical Julia-Lythgoe olefination, using sulfoxides instead of sulfones, affords, after in situ benzoylation and SmI 2 /HMPA or SmI 2 /DMPU-mediated reductive elimination, 1,2-di-, tri- and tetrasubstituted olefins in moderate to good yields and E / Z selectivity. The conditions are mild and the procedure is widely applicable. The reaction mechanism was studied and a general model, describing the reaction selectivity, is proposed.