1333412-65-9Relevant academic research and scientific papers
Synthesis, structure and catalytic properties of CNN pincer palladium(II) and ruthenium(II) complexes with N-substituted-2-aminomethyl-6-phenylpyridines
Wang, Tao,Hao, Xin-Qi,Zhang, Xiao-Xue,Gong, Jun-Fang,Song, Mao-Ping
, p. 8964 - 8976 (2011/10/31)
N-substituted-2-aminomethyl-6-phenylpyridines 2a-c have been easily prepared from commercially available 6-bromo-2-picolinaldehyde in two steps. Reaction of 2a-c with PdCl2 in toluene in the presence of triethylamine gave the CNN pincer Pd(ii) complexes 3a-c in 18-28% yields. The CNN pincer Ru(ii) complex 5 containing a Ru-NHR functionality could be obtained in a 71% yield by treatment of 2c with a Ru(ii) precursor instead of PdCl 2. Additionally, the related CNN pincer Ru(ii) complex 7 containing a Ru-NH2 functionality has been synthesized by the reaction of 2-aminomethyl-6-phenylpyridine with the same Ru(ii) precursor in a 68% yield. All the new compounds were characterized by elemental analysis (MS for ligands), 1H, 13C NMR, 31P{1H} NMR (for Ru complexes) and IR spectra. Molecular structures of Pd complex 3c as well as Ru complexes 5 and 7 have been determined by X-ray single-crystal diffraction. The obtained Pd complexes 3a-c were effective catalysts for the allylation of aldehydes as well as for three-component allylation of aldehydes, arylamines and allyltributyltin and their activity was found to be much higher than a related NCN Pd(ii) pincer in the allylation of aldehyde. On the other hand, the two new CNN pincer Ru(ii) complexes 5 and 7 displayed excellent catalytic activity in the transfer hydrogenation of ketones in refluxing 2-propanol with the latter being much more active. The final TOF values were up to 4510 h-1 with 0.01 mol% of 5 and 220800 h-1 with 0.005 mol% of 7, respectively. The Royal Society of Chemistry 2011.
