Reactions of palladium complex of N,N-dimethylbenzylamine with aromatic phosphines bearing the methoxy groups at the 2,6-positions

Reactions of [(C6H4CH2NMe2-C2,N)PdCl]2 (1) with (2,6-dimethoxyphenyl)diphenylphosphine (MDMPP), bis(2,6-dimethoxyphenyl)phenylphosphine (BDMPP), and tris(2,6-dimethoxyphenyl)phosphine (TDMPP) gave the corresponding complexes [(C6H4CH2NMe2-C2,N)PdCl(L)] (2a: L=MDMPP; 2b: L=BDMMP; 2c: L=TDMPP). Reactions of 2 with NaPF6 led to replacement of the Cl atom with the methoxy-O atom to form the corresponding complexes [(C6H4CH2NMe2-C2,N)Pd(L)](PF6) (3). On treatment of 3 with HCl (aq), protonation occurred at the N atom in 3 to give [(C6H4CH2NHMe2-C2)PdCl(L)] (5). Based on X-ray structural analyses of 2c, 3a, 3b, 5a and 5c, complexes (2b, 2c, 3b, 3c, 5b and 5c) bearing BDMPP and TDMPP ligands have square-pyramidal structures with a P–O coordination in the axial position and complexes (2a, 3a and 5a) bearing MDMPP have square planar structures. When a complex bearing triphenylphosphine [(C6H4CH2NMe2-C2,N)PdCl(PPh3)] was treated with NaPF6, [(C6H4CH2NMe2-C2,N)Pd(PPh3)(O2H)](PF6) (4) bearing a H2O ligand was obtained. The reaction with HCl (aq) led to a cleavage of a Pd–C bond to give [PdCl3(PPh3)][PhCH2NHMe2] (6). X-ray analyses of 4 and 6 were also carried out. Reactions of 1 or 2a with mesityl isocyanide (MesNC) proceeded with replacement of a Cl atom with isocyanide and insertion of isocyanide to produce [(C6H4CH2NMe2-C2,N)PdCl(MesNC)] (7) and [C6H4CH2NMe2-C2)PdCl(MesNC)2] (8).