Allylcopper intermediates with N-heterocyclic carbene ligands: synthesis, structure, and catalysis.

Allylcopper intermediates with N-heterocyclic carbene ligands are synthesized by transmetalation of allylsiloxane reagents, and the crystal structures of allylcopper compounds are reported. The allylcopper transmetalation is utilized for catalytic aldehyde allylation, which is found to be facilitated by a trifluorosilane co-catalyst.