Synthesis and structure of orthopalladated complexes derived from prochiral iminophosphoranes and phosphorus ylides

The iminophosphorane Ph2MeP=NPh (1) reacts with Pd(OAc)(2) to give the orthopalladated [Pd(mu-Cl) (C6H4(PPh(Me)=NPh-kappa-C,N)(2)}](2) (2) as the racemic mixture, which reacts with Tl(acac) to give [Pd(acac) [C6H4(PPh(Me)=NPh-kappa-C,N)-2}] (3). The X-ray structure of (3) has been determined by diffraction methods. The phosphorus ylide Ph2MeP=CHC(O)Ph (5) reacts with Pd(OAC)(2) to give the dinuclear [Pd(mu-Cl){C6H4(PPh(Me)CHC(O)Ph-kappa-C,C)-2)](2) (6) as a mixture of isomers. Complex (6) reacts with Tl(acac), PPh3 or AgClO4/ dppe giving the mononuclear derivatives [Pd(acac){C6H4(PPh(Me)CHC(O)Ph-kappa-C,C)-2}] (7), [PdCl{C6H4(PPh(Me)CHC(O)Ph-kappa-C,C)2)PPh3](8) and [Pd{C6H4(PPh(Me)CHC(O)Ph-kappa-C,C)-2}(dppe-P,P')](ClO4) (9), as mixtures of stereoisomers with high diastereomeric excess. (C) 2007 Elsevier B.V. All rights reserved.