The Application Of Palladium Complexes Containing P-N Hybrid Ligand In C-C Decarboxylative Cross-coupling Reaction

The palladium-catalyzed decarboxylative cross-coupling reaction is one of theeffective routes in the formation of a great range of bi-aryl compounds withstraightforward procedures in recent years. N-donor and P-donor ligands are widelyused in these catalytic reaction systems. In this thesis, the catalytic performance of apalladium complex containing P-N hybrid ligand bdppmapy (N,N-bis-(diphenylphosphanylmethyl)-2-aminopyridine) was investigated during thedecarboxylative cross-coupling reactions. The works contain three parts:1) The progress of decarboxylative cross-coupling reactions was reviewed, whiledevelopments on substrates and catalysts were discussed respectively。2) Reaction of bdppmapy with PdCl2afforded a mononuclear complex[(bdppmapy)PdCl2](1). Compound1was characterized by elemental analysis, IR,1H,13C and31P NMR, Electrospray ion mass spectra (ESI-MS) and X-ray single crystalcrystallography. The Pd(II) center in1is chelated by bdppmapy, showing a cis-squareplanar geometry. With the assistance of additive Cu2O, complex1exhibited goodcatalytic activity toward the decarboxylative cross-coupling reactions between4-picolinic acid and aryl bromides. In the presence of only2mol%catalyst, a family of4-aryl-pyridines could be isolated in up to83%yield.3) Compound1was employed as catalyst in three decarboxylative cross-couplingreaction systems: the reaction between2-nitrobenzonic acid and2,4-dimethoxybromobenzene, the reaction between2-nitrobenzonic and2,4-dimethoxybenzonic acid,and the reaction between4-methoxybenzonic acid and2-phenylpyridine. Aspectscontaining the palladium salts, the additives and the reaction temperatures wereexplored, whereas the catalytic performance of1toward these reactions were found tobe inadequate.