108100-06-7Relevant articles and documents
Polystyrene-supported enantiopure 1,2-diamines: Development of a most practical catalyst for the asymmetric transfer hydrogenation of ketones
Marcos, Rocio,Jimeno, Ciril,Pericas, Miquel A.
, p. 1345 - 1352 (2011)
Chlorosulfonylated polystyrene, a commodity resin, reacts with enantiopure 1,2-diamines to afford, in a single step, high loading catalytic resins involving monosulfonylated 1,2-diamino moieties. These functional polymers form stable (p-cymene)ruthenium chloride [RuCl(p-cymene)] complexes that efficiently catalyze (down to S/C=150) the asymmetric transfer hydrogenation (ATH) of alkyl aryl ketones with formic acid-triethylamine under essentially solvent-free (down to 0.25 mLmmol-1) reaction conditions. Among these resins, the immobilized version of TsDPEN stands out as a most practical catalyst for ATH: Uniformly high enantioselectivities are achieved with its use at low catalyst loading, and the resin can be recycled with virtually no limits.
Bis-paracyclophane N-heterocyclic carbene-ruthenium catalyzed asymmetric ketone hydrosilylation
Song, Chun,Ma, Changqin,Ma, Yudao,Feng, Wenhua,Ma, Shutao,Chai, Qiang,Andrus, Merritt B.
, p. 3241 - 3244 (2005)
New chiral bis-paracyclophane N-heterocyclic carbene (NHC) ligands 1-3 have been explored for ruthenium catalyzed asymmetric hydrosilylation of ketones using diphenylsilane to give enantioenriched alcohols. These ligands provide for efficient asymmetric reduction in the presence of silver(I) triflate (1 mol %) at room temperature with high reactivity and selectivity. Acetophenone 4 was reduced with 1 mol % catalyst in 96% isolated yield, 97% ee. Following removal of the silyl ether, various alcohols 5 were obtained from aromatic ketones in high yield and selectivity.
Heterogeneous enantioselective hydrogenation of aromatic ketones catalyzed by cinchona- and phosphine-modified iridium catalysts
Jiang, He-Yan,Yang, Chao-Fen,Li, Chun,Fu, Hai-Yan,Chen, Hua,Li, Rui-Xiang,Li, Xian-Jun
, p. 9240 - 9244 (2008)
(Chemical Equation Presented) Catalyst support: The first highly enantioselective heterogeneous hydrogenation of aromatic ketones catalyzed by Ir/SiO2 stabilized with Ph3P and modified by a chiral diamine derived from a cinchona alkaloid is described (see scheme). The reaction can be employed for the reduction of a broad range of aromatic ketones to the corresponding alcohols with high enantioselectivity.
Ruthenium(II) trerdentate CNN complexes: Superlative catalysts for the hydrogen-transfer reduction of ketones by reversible insertion of a carbonyl group into the Ru-H bond
Baratta, Walter,Chelucci, Giorgio,Gladiali, Serafino,Siega, Katia,Toniutti, Micaela,Zanette, Matteo,Zangrando, Ennio,Rigo, Pierluigi
, p. 6214 - 6219 (2005)
(Chemical Equation Presented) Very low loading and short reaction times are characteristic features of the quantitative reduction of different ketones using 2-propanol and terdentate [RuX(CNN)-(dppb)] (X = H, Cl (see structure); dppb = Ph2P(CH2)4PPh2) complexes prepared from 6-(4′-methylphenyl)-2-pyridyl-methylamine. The reduction apparently takes place by reversible insertion of the substrate into the Ru-H bond, thus leading to a RuII alkoxide.
Synthesis of novel chiral tetraaza ligands and their application in enantioselective transfer hydrogenation of ketones
Yu, Shen Luan,Li, Yan Yun,Dong, Zhen Rong,Gao, Jing Xing
, p. 395 - 398 (2012)
Novel chiral tetraaza ligands (R)-N, N′-bis[2-(piperidin-1-yl) benzylidene]propane-1, 2-diamine 6 and (S)-N-[2-(piperidin-1-yl)benzylidene]-3- {[2-(piperidin-1-yl)benzylidene]amino}-alanine sodium salt 7 have been synthesized and fully characterized by NM
Ruthenium-catalysed efficient asymmetric transfer hydrogenation of aromatic ketones using cinchona alkaloids as chiral ligands
Jiang, Heyan
, p. 761 - 763 (2013)
Cinchona alkaloid derivatives were applied in asymmetric transfer hydrogenation of aromatic ketones in a ruthenium catalytic system using i-PrOH as the hydrogen source. A series of aromatic ketones could be transfer-hydrogenated to the corresponding alcohols with good to excellent conversion and enantioselectivity. The best results were achieved using 9-amino(9-deoxy) epiquinidine as the ligand; the enantioselectivity with acetophenone and 2′-(trifluoromethyl)acetophenone could reach 90% ee.
Asymmetric hydrogenation of aromatic ketones using new chiral-bridged diphosphine/diamine-Ru(II) complexes
Cui, Yu Ming,Wang, Lai Lai,Kwong, Fuk Yee,Sun, Wei
, p. 1403 - 1406 (2010)
A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new ((Rax)-BuP)/(R,R)-DPEN-Ru(II) complex catalyst system. The hydrogenation of 2-methylacetophenone in n-butanol (t-BuOK/Ru=45.6/1, S/C=500, 20atm. of H2, 20°C, 48h) afforded (S)-1-(2′-methylphenyl)ethanol in 92% ee and >99% conversion.
Asymmetric hydrogenation of isobutyrophenone using a [(diphosphine) RuCl2 (1,4-diamine)] catalyst
Grasa, Gabriela A.,Zanotti-Gerosa, Antonio,Medlock, Jonathan A.,Hems, William P.
, p. 1449 - 1451 (2005)
(Chemical Equation Presented) The use of three chiral 1,4-diamines in the [(diphosphine) RuCl2 (diamine)] catalyst system is demonstrated in the hydrogenation of acetophenone. The use of a 1,4-diamine offers unique properties that allow tuning of the catalyst system. These include the first example of the use of a racemic diamine in combination with a chiral phosphine, which gives 95% ee in the hydrogenation of isobutyrophenone
Dinuclear zinc complex catalyzed asymmetric methylation and alkynylation of aromatic aldehydes
Liu, Shanshan,Li, Gao-Wei,Yang, Xiao-Chao,Zhang, De-Yang,Wang, Min-Can
, p. 7147 - 7156 (2017)
A general AzePhenol dinuclear zinc catalytic system has been successfully developed and introduced into the asymmetric addition of dimethylzinc and alkynylzinc to aromatic aldehydes. In this system, an azetidine derived chiral ligand has proven to be an effective enantioselective promoter. Under the optimal reaction conditions, a series of chiral 1-hydroxyethyl (up to 99% ee) and secondary propargylic alcohols (up to 96% ee) were generated with good yields and enantioselectivities. Additionally, this novel catalytic system showed good functional group compatibility. Remarkably, the substituent's electronic nature alone is not sufficient to allow for exclusive enantioselectivity, an additional substituent's location also had an effect. We proposed that the formation of a stable and structural rigid transition state by the chelation of ortho substituted benzaldehydes to the zinc atom was responsible for the observed higher enantioselectivity. The possible catalytic cycles of both transformations accounting for the stereoselectivity were described accordingly.
Isonitrile Iron(II) complexes with chiral N2P2 macrocycles in the enantioselective transfer hydrogenation of ketones
Bigler, Raphael,Mezzetti, Antonio
, p. 6460 - 6463 (2014)
Bis(isonitrile) iron(II) complexes bearing a C2-symmetric N2P2 macrocyclic ligand, which are easily prepared from the corresponding bis(acetonitrile) analogue, catalyze the asymmetric transfer hydrogenation (ATH) of a broad scope of ketones in excellent yields (up to 98%) and with high enantioselectivity (up to 91% ee).