1475-13-4Relevant articles and documents
1,3,4-Oxadiazole-functionalizedα-amino-phosphonates as ligands for the ruthenium-catalyzed reduction of ketones
Hkiri, Shaima,Gourlaouen, Christophe,Touil, Soufiane,Samarat, Ali,Sémeril, David
, p. 11327 - 11335 (2021)
Threeα-aminophosphonates, namely diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-trifluoromethylphenyl) methyl]phosphonate (3a), diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(2-methoxyphenyl)methyl]phosphonate (3b) and diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-nitrophenyl)methyl]phosphonate (3c), were synthetizedviathe Pudovik-type reaction between diethyl phosphite and imines, obtained from 5-phenyl-1,2,4-oxadiazol-2-amine and aromatic aldehydes, under microwave irradiation. Compounds3a-cunderwent complexation with a ruthenium(ii) precursor, selectively at the more basic nitrogen atom of the oxadiazole ring, leading to the corresponding ruthenium complexes4a-cof the formula [RuCl2(L)(p-cymene)] (L= α-aminophosphonates3a-c). Complexes4a-cproved to be efficient catalysts for the transfer hydrogenation of ketones to alcohols. All new compounds were fully characterised by elemental analysis, infrared, mass and NMR spectroscopy. An X-ray structure of the α-aminophosphonate3bwas obtained and revealed the presence, in the solid state, of an infinite chain of3bunits supramolecularly interlinked. Two X-ray diffraction studies carried out on ruthenium complexes confirm the specific coordination of the electron-enricher nitrogen atom of the oxadiazole ring.
Ruthenium complexes of phosphine-amide based ligands as efficient catalysts for transfer hydrogenation reactions
Yadav, Samanta,Vijayan, Paranthaman,Yadav, Sunil,Gupta, Rajeev
, p. 3269 - 3279 (2021/03/16)
This work presents three mononuclear Ru(ii) complexes of tridentate phosphine-carboxamide based ligands providing a NNP coordination environment. The octahedral Ru(ii) ion shows additional coordination with co-ligands; CO, Cl and CH3OH. All three Ru(ii) complexes were thoroughly characterized including their crystal structures. These Ru(ii) complexes were utilized as catalysts for the transfer hydrogenation of assorted carbonyl compounds, including some challenging biologically relevant substrates, using isopropanol as the hydrogen source. The binding studies illustrated the coordination of the isopropoxide ion by replacing a Ru-ligated chloride ion followed by the generation of the Ru-H intermediate that was isolated and characterized and was found to be involved in the catalysis.
Aza-crown compounds synthesised by the self-condensation of 2-amino-benzyl alcohol over a pincer ruthenium catalyst and applied in the transfer hydrogenation of ketones
Zhang, Shanshan,Wang, Zheng,Cao, Qianrong,Yue, Erlin,Liu, Qingbin,Ma, Yanping,Liang, Tongling,Sun, Wen-Hua
supporting information, p. 15821 - 15827 (2020/11/24)
A well-defined PNN-Ru catalyst was revisited to self-condense 2-aminobenzyl alcohol in forming a series of novel aza-crown compounds [aza-12-crown-3 (1), aza-16-crown-4 (2) and aza-20-crown-5 (3)]. All aza-crown compounds are separated and determined by NMR, IR, and ESI-MS spectroscopy as well as X-ray crystallography, indicating the saddle structure of 1 and the twisted 1,3-alternate conformation structure of 3. These aza-crown compounds have been explored to study ferric initiation of transfer hydrogenation (TH) of ketones into their corresponding secondary alcohols in the presence of 2-propanol with a basic t-BuOK solution, achieving a high conversion (up to 95%) by a ferric complex with 2 in a low loading (0.05 mol%). This journal is
