126253-79-0Relevant academic research and scientific papers
Five- and six-membered exo-cyclopalladated compounds of N-benzylideneamines. Synthesis and X-ray crystal structure of [PdBr{p-MeOC6H3(CH2) 2N=CH(2,6-Cl2C6H3)}(PPh 3)] and [PdBr{C6H4CH2N=CH(2,6-Cl2C 6H3)}(PEt3)2]
Albert, Joan,Gómez, Montserrat,Granell, Jaume,Sales, Joaquim,Solans, Xavier
, p. 1405 - 1413 (2008/10/08)
The reaction of N-(2,6-dichlorobenzylidene)amines, 2,6-Cl2C6H3CH=N(CH2) nC6H4-p-R (n = 1, 2; R = H, MeO), with Pd(AcO)2 in refluxing acetic acid has been studied. With N-benzylidenebenzylamines (n = 1) exo five-membered derivatives were obtained. From N-benzylidene(2-phenylethyl)amines (n = 2) endo five-membered cyclopalladated compounds were formed by oxidative addition of C-Cl bonds of the ligand to Pd(0) formed in situ. Under milder conditions (acetic acid at 80°C) the exo six-membered compound [Pd(AcO){p-MeOC6H3(CH2) 2N=CH(2,6-Cl2C6H3)}]2 was obtained. All exo derivatives contain the imine ligand in the syn form. By reaction with PR3 (R = Et, Ph), monophosphine complexes [PdX(CN)(PR3)] and bisphosphine derivatives [PdX(CN)(PR3)2], where the Pd-N bond has been broken, can be obtained. [PdBr{p-MeOC6H3(CH2) 2N=CH(2,6-Cl2C6H3)}(PPh 3)] (6f) crystallizes in the monoclinic space group P21/n with a = 20.321 (4) A?, b = 12.561 (3) A?, c = 12.608 (3) A?, β = 97.50 (2)°, and Z = 4. The exo six-membered ring displays a boat conformation with Pd and C(7) atoms out of the plane defined by the remaining atoms. [PdBr{C6H4CH2N=CH(2,6-Cl2C 6H3)}(PEt3)2] (9c) has been characterized by X-ray crystallography; it crystallizes in the monoclinic space group P21/a with a = 45.352 (6) A?, b = 8.884 (2) A?, c = 7.556 (2) A?, β = 99.02 (3)°, and Z = 4. The Pd atom has a roughly planar coordination, and the imine ligand is in the anti form.
