Synthesis, Structures, and Catalytic Properties of Late-Transition-Metal 2,6-Bis(2-phosphaethenyl)pyridine Complexes

2,6-Bis(2-phosphaethenyl)pyridine (PNP) complexes of Rh(I), Cu(I), and Ag(I) have been prepared and examined by NMR and X-ray diffraction analyses. The PNP ligand adopts κ 3 (P,N,P) coordination for Rh(I) and Cu(I) and κ 2 (P,P) coordination for Ag(I). The rhodium complex [RhCl(PNP)] in combination with AgOTf catalyzes conjugate addition of benzyl carbamate to enones.