Copper-Catalyzed Conjugate Additions to Isocyanoalkenes

A copper iodide–Pyox complex catalyzes the first conjugate addition of diverse sulfur, nitrogen, and carbon nucleophiles to isocyanoalkenes. The anionic addition generates metalated isocyanoalkanes capable of S N i displacements, providing a rapid route to a series of functionalized, cyclic isocyanoalkanes. The Cu(I)I–Pyox complex efficiently catalyzes a first-in-class conjugate addition affording a range of complex, functionalized isocyanoalkanes that are otherwise challenging to synthesize while laying a foundation for catalytic reactions that maintain the isocyanide group.