Copper-Catalyzed Enantio-, Diastereo-, and Regioselective [2,3]-Rearrangements of Iodonium Ylides

The first highly enantioselective, diastereoselective, and regioselective [2,3]-rearrangement of iodonium ylides has been developed as a general solution to catalytic onium ylide rearrangements. In the presence of a chiral copper catalyst, substituted allylic iodides couple with alpha-diazoesters to generate metal-coordinated iodonium ylides, which undergo [2,3]-rearrangements with high selectivities (up to >95: 5 r.r., up to >95: 5 d.r., and up to 97% ee). The enantioenriched iodoester products can be converted stereospecifically into a variety of onium ylide rearrangement products, as well as compounds that are not accessible by classical onium ylide rearrangements.