Metal-catalyzed ylide formation and [2,3] sigmatropic rearrangement of allyl sulfides with trimethylsilyldiazomethane

Trimethylsilyldiazomethane is compared with ethyl diazoacetate for the rhodium, copper, and cobalt catalyzed formation and [2,3] rearrangement of allylsulfonium ylides. At room temperature, the reaction can be carried out using the allyl sulfide as the limiting reagent by slow addition of 3 equivalents of the diazo compound. Slightly better yields were obtained with trimethylsilyldiazomethane than with ethyl diazoacetate.