CONTEXT

Butadienyl phosphines are molecules that are interesting in coordination chemistry and catalysis since they combine two very well-known ligands: phosphines and conjugated dienes. However, these molecules have never been used in catalysis, probably because existing synthetic routes are neither general nor efficient.

Very few examples of butadienyl phosphines are described in the literature. In the context of our studies on highly nucleophilic metalated ylides, we recently discovered a new, general, one-pot synthetic route to prepare these potential ligands. The first example of a catalytic reaction using butadienyl phosphines is thus described. We found that 4-phenyl-1,3-butadienyldiphenylphosphine 4 is indeed an excellent ligand for Ullmann-type copper catalyzed arylations of N- and O-nucleophiles. Moreover, by following the reactions using 31P NMR, we are also able to propose a mechanism.