Two original complexes featuring an (amino)(phosphino)carbene η2-bonded to the metal have been obtained in 60% and 80% yields, by addition of the corresponding stablecarbene to PdCl2(cod) and NiCl2(PPh3)2, respectively. Both complexes have been fully characterized including X-ray diffraction studies. The catalytic activity of the palladium complex has been evaluated for aryl amination reactions.
Direct complexation of (amino)(phosphino)carbene la and (amino)(oxy)carbene 1b featuring a phosphino group in position-6 to the carbene with [Rh(CO)(2)Cl](2) has been studied. With the 1,2-bidentate ligand 1a, an original cationic complex 2 featuring two (amino)(phosphino)carbenes eta(2)-bonded to the metal has been isolated in 79% yield. In the case of the 1,6-bidentate ligand 1b, a rhodium(1) complex 3 in which the carbene is in trans position relative to the CO ligand was obtained in 85% yield. Both compounds were fully characterized including X-ray diffraction studies. (C) 2004 Elsevier B.V. All rights reserved.
(Amino)(phosphino)carbenes are stable due to the donation of the nitrogen lone pair, the phosphino group remains strongly pyramidalized. Reactions can be performed selectively at the carbene center, but also at the phosphorus center leading to new stable carbenes. These difunctional molecules can be considered as hybrid ligands.