120523-12-8Relevant articles and documents
Ruthenium ONO-type pincer complex: Synthesis, structural characterization, and catalysis
Zhang, Yao,Li, Xingwei,Hong, Soon Hyeok
, p. 1779 - 1783 (2010)
A novel nitrone-based pincer ligand was developed by a single-step synthesis from N-(tert-butyl)hydroxylamine acetate and 2,6- pyridinedicarboxaldehyde. The developed ligand allowed us to synthesize a cationic ruthenium pincer complex. A distorted octahedral coordination environment around the ruthenium center was observed. The complex showed excellent catalytic activity in transfer hydrogenation reactions with turnover numbers up to 590,000.
Hydrogen-transfer catalyzed by half-sandwich Ru(II) aminophosphine complexes
Standfest-Hauser,Slugovc,Mereiter,Schmid,Kirchner,Xiaoc,Weissensteiner
, p. 2989 - 2995 (2001)
The syntheses of and catalytic studies on some Ru(II) complexes bearing the aminophosphine ligands N,N-dimethyl-2-diphenylphosphinoethylamine (PN), optically pure (RC,Spl)-2-{1-(N,N-dimethylamino)ethyl}-1- diphenylphosphinoferrocene(PPFA), and N,N-dimethyl-2-diphenylphosphinoaniline (DBD) are described, [RuCp(CH3CN)3]+ reacts with these ligands to give the cationic complexes [RuCp(PN-κN,κP)(CH3CN)]+ (1a), [(SRu,RC,Spl)-RuCp(PPFA-κN,κP) (CH3CN)]+ (1b), and [RuCp(DBD-κN,κP)(CH3CN)]+ (1c), respectively, in high yields. From these, in turn, the residual CH3CN ligand can be replaced by Br- upon addition of NEt4Br in CH2Cl2, resulting in the formation of the neutral complexes RuCp(PN)Br (2a), (SRu,RC,Spl)-RuCp(PPFA)Br (2b), and RuCp(DBD)Br (2c), again in good yields. Similarly, [Ru(η6-p-cymene)Cl2]2 reacts with 1 equiv. of PN or PPFA to give Ru(η6-p-cymene)(PN-κP)Cl2 (3a) and Ru(η6-p-cymene)(PPFA-κP)Cl2 (3b). Furthermore, treatment of 3 with TlCF3SO3 in THF at room temperature affords the cationic complexes [Ru(η6-p-cymene)(PN-κN,κP)Cl]CF3SO 3 (4a) and [(RRu,RC,Spl)-Ru (η6-p-cymene)-(PPFA-κN,κP)Cl]CF3SO 3 (4b). The absolute configuration at the metal center of 2b and 4b′ (BPh4- salt of 4b) was determined by X-ray crystallography. Catalytic studies were performed with the racemic complexes 1a, 2a, 2c, and 4a and the diastereopure complexes 1b, 2b, and 4b. All of these proved to be excellent precatalysts for the transfer hydrogenation of acetophenone and derivatives thereof, and cyclohexanone. With the enantiomerically pure systems 2b and 4b, only racemic products were obtained. This testifies to the hemilabile nature of the aforementioned aminophosphine ligands giving transient κ-P-bonding coordination. Since diastereoface selection of incoming substrates is based on the planar chirality of the ferrocene moiety, rather than the metal centered chirality, no enantioselective reaction takes place.
Efficient transfer hydrogenation reactions with quinazoline-based ruthenium complexes
Karabuga, Semistan,Bars, Songul,Karakaya, Idris,Gumus, Selcuk
, p. 101 - 104 (2015)
(4-Phenylquinazolin-2-yl)methanamine was synthesized in high yield by starting from naturally and commercially available glycine in a few steps. The ligand was reacted with RuCl2(PPh3)3 and RuCl2(PPh3)dppb to obtain N-heterocyclic ruthenium(II) complexes. We have examined these catalysts in transfer hydrogenation of acetophenone derivatives and excellent conversions of up to 99% and high TOF values of up to 118,800 h-1 using 0.1 mol % of catalyst were achieved.
Synthesis, structure, and photophysical properties of tributyl phosphine bisbenzothienyl iridium(III) complex and its application on transfer hydrogenation of acetophenone
Wang, Dawei,Zhao, Keyan,Yang, Shuyan,Ding, Yuqiang
, p. 400 - 404 (2015)
A phosphine bisbenzothienyl iridium(III) complex was synthesized and characterized by IR and1H NMR spectroscopy as well as X-ray diffraction methods. The TG data suggests that the complex has an excellent thermal stability than that with an amidate ancillary ligand. Photophysical properties showed that the complex emits typical green emission.
Diastereoselectivity and catalytic activity in ruthenium complexes chiral at the metal centre
Zerla, Daniele S.,Rimoldi, Isabella,Cesarotti, Edoardo,Facchetti, Giorgio,Pellizzoni, Michela,Fusè, Marco
, p. 2 - 8 (2014)
Cis-RuCl2(diphosphine)(CAMPY) complexes, chiral at the metal centre with matching or mismatching chiralities between diphosphine and CAMPY were prepared and the configuration at the metal was determined in solution by a complete set of NMR investigations; CAMPY is (R)-(-) or (S)-(+)-8-amino-5,6,7,8-tetrahydroquinoline. The complexes were used in ATH reactions of different aryl ketones with 2-propanol as hydrogen source. The effects of the chirality at the metal were studied and enantiomeric excesses up to 99% were obtained.
Synthesis, characterization of novel Nickel(II) complexes with PxNy-Type ligands and their application in reduction of ketones
Wang, Zhe,Yu, Shen-Luan,Wei, Zan-Bin,An, Dong-Li,Li, Yan-Yun,Gao, Jing-Xing
, (2019)
Novel nickel(II) complexes 1 and 2 could be conveniently prepared using PxNy-type ligands and easily available NiCl2·6H2O as a starting material. Furthermore, we obtained the single crystals suitable for X-ray diffraction to confirm the structure of these two nickel(II) complexes. With the well-designed nickel(II) complex, the hydrogenation of a wide range of ketones proceeded smoothly under relative mild reaction conditions, affording the corresponding alcohols with high isolated yields.
In situ formation of ligand and catalyst - Application in ruthenium-catalyzed enantioselective reduction of ketones
Vaestilae, Patrik,Wettergren, Jenny,Adolfsson, Hans
, p. 4039 - 4041 (2005)
The direct in situ formation of highly efficient ruthenium-catalysts for the asymmetric reduction of ketones was obtained by combining chiral ligand building blocks with a ruthenium precursor. The Royal Society of Chemistry 2005.
Dinuclear Di(N-heterocyclic carbene) iridium(III) complexes as catalysts in transfer hydrogenation
Volpe, Andrea,Baldino, Salvatore,Tubaro, Cristina,Baratta, Walter,Basato, Marino,Graiff, Claudia
, p. 247 - 251 (2016)
Two novel di(N-heterocyclic carbene) complexes of formula (μ-PyrIm-CH2-ImPyr)[IrCp?Cl]2(PF6)2 (1) and μ-MeIm-CH2(p-C6H2)CH2-ImMe[IrCp? Cl]2 (2) (Im = imidazol-2-ylidene) have been synthesised by transmetallation of the dicarbene ligand from the corresponding dicarbene silver complex, using [IrCp?(μ-Cl)Cl]2 as an iridium precursor. The structure of complex 2 has been determined by X-ray diffraction and is characterized by a double ortho-metallation of the p-xylylene bridge between the carbene units. Both complexes show good activity in the transfer hydrogenation of ketones to alcohols in 2-propanol. Dinuclear iridium(III) complexes bearing a bridging di(NHC) ligand have been synthesised and tested as catalysts in transfer hydrogenation reactions.
α-amino acidate-Ru(II) catalysts for asymmetric transfer hydrogenation: First utilization of α-amino acids as an efficient ligand
Ohta, Tetsuo,Nakahara, Shu-Ichi,Shigemura, Yasuhiko,Hattori, Kouichi,Furukawa, Isao
, p. 491 - 492 (1998)
Ruthenium complexes, prepared by mixing potassium salt of α-amino acids and [RuCl2(arene)]2, acted as catalysts for asymmetric transfer hydrogenation of ketones from 2-propanol in the presence of KOH, and enantiomeric excesses of the products reached 92%.
Preparation, Characterization, and Catalytic Reactions of NCN Pincer Iron Complexes Containing Stannyl, Silyl, Methyl, and Phenyl Ligands
Ito, Jun-Ichi,Hosokawa, Satomi,Khalid, Hairuzana Binti,Nishiyama, Hisao
, p. 1377 - 1383 (2015)
Preparation and reactivity of chiral and achiral NCN pincer Fe complexes containing bis(oxazolinyl)phenyl (abbreviated as phebox) ligands with SnMe3, SiMe3, Me, and Ph ligands were investigated. Irradiation of (phebox)SnMe3 (2) with 1 equiv of Fe(CO)5 led to oxidative addition to give NCN pincer stannyl complex (phebox)Fe(CO)2(SnMe3) (3). Similarly, oxidative addition of (phebox)SiMe3 (4) with Fe(CO)5 resulted in the formation of silyl complex (phebox)Fe(CO)2SiMe3 (5). Me and Ph complexes (phebox)Fe(CO)2R (7, R = Me; 8, R = Ph) were synthesized by transmetalation of the bromide complex (phebox)Fe(CO)2Br (1) with ZnMe2 and ZnPh2, respectively. These phebox Fe complexes served as catalysts for hydrosilylation of a ketone and C-H silylation of N-methylindole. (Chemical Equation Presented).
