102225-84-3Relevant academic research and scientific papers
Synthesis of NHC-Oxazoline Pincer Complexes of Rh and Ru and Their Catalytic Activity for Hydrogenation and Conjugate Reduction
Ito, Jun-Ichi,Sugino, Kanae,Matsushima, Satoru,Sakaguchi, Hiroki,Iwata, Hiroshi,Ishihara, Takahiro,Nishiyama, Hisao
, p. 1885 - 1894 (2016)
We describe the preparation and catalytic reactions of new CCN pincer Rh and Ru complexes containing NCH-oxazoline hybrid ligands. Oxazolinyl-phenyl-imidazolium derivatives (3) were suitable ligand precursors for the CCN pincer scaffold. C-H bond activation of 3 with RhCl3·3H2O in the presence of NEt3 yielded the desired CCN pincer Rh complexes 5 in 13-27% yields. The related CCN pincer Ru complexes 8-10 were synthesized in good yields by C-H bond activation of p-cymene Ru complexes 7 in the presence of NaOAc in DMF. The chiral complexes 8 and 9 had two diastereomers according to the coordination of CO and OAc ligands. The CCN Rh complexes showed catalytic activity for conjugate reduction of ethyl β-methylcinnamate with hydrosilane, with moderate enantioselectivity. The CCN Ru complexes were found to be active in the hydrogenation of aromatic ketones. In particular, hydrogenation of 9-acetylanthracene took place at not only the C=O bond but also the anthracene ring. The Ru complexes were also used as catalysts in the transfer hydrogenation of 9-acetylanthracene with 2-propanol; again, both the C=O bond and the anthracene ring were hydrogenated.
