Stereospecific Cu(I)-catalyzed C-O cross-coupling synthesis of acyclic 1,2-di- and trisubstituted vinylic ethers from alcohols and vinylic halides.

We report a robust method catalyzed by CuI and trans-N,N'-dimethylcyclohexyldiamine, enabling single-step C-O bond cross-coupling between 1,2-di- and trisubstituted vinylic halides with a variety of functionalized alcohols, pro-ducing acyclic vinylic ethers. In contrast with previous reports, this stereospecific transformation selectively gives each of the (E)- and (Z)-vinylic ether products from the corresponding vinylic halide precursors. This method is compatible with carbohydrate-derived primary and secondary alcohols, and several other functional groups. The conditions are mild enough to reliably generate vinylic allylic ethers without promoting Claisen rearrangements.