115510-91-3Relevant academic research and scientific papers
Highly enantioselective synthesis of heteroaromatic alcohols catalyzed by chiral diaminodiphosphine-ruthenium(II) complexes
Shen, Wei-Yi,Li, Yan-Yun,Dong, Zhen-Rong,Gao, Jing-Xing
, p. 2413 - 2417 (2009)
Chiral diaminodiphosphine-ruthenium(II) complexes were found to be excellent catalysts for the asymmetric transfer hydrogenation of heteroaromatic ketones in propan-2-ol. In the presence of potassium hydroxide, the enantioselective reduction of heteroaromatic ketones proceeded smoothly to give chiral alcohols with excellent enantiomeric excess (up to 97% ee) under mild conditions without reduction of the heterocycle. Georg Thieme Verlag Stuttgart.
Rhodium(I)-catalysed Asymmetric Hydrosilylation of Ketones using New Diferrocenyl Dichalcogenides (R,S)-Fe(C5H5)>2 (E = S, Se, Te), as Chiral Ligands
Nishibayashi, Yoshiaki,Singh, Jai Deo,Segawa, Kyohei,Fukuzawa, Shin-ichi,Uemura, Sakae
, p. 1375 - 1376 (1994)
The new chiral compounds, (R,S)-di dichalcogenides (R,S)-Fe(C5H5)>2 (E = S, Se, Te), work effectively as chiral ligands for the rhodium(I)-catalysed asymmetric hydrosilylation of alkyl aryl ketones resulting in high enantiomeric excess and moderate chemical yields.
Asymmetric reduction of ketones by biocatalysis using medlar (Mespilus germanica L) fruit grown in Algeria
Bennamane, Manhel,Zeror, Saousen,Aribi-Zouioueche, Louisa
, p. 327 - 332 (2014)
The biocatalytic reduction of ketones was performed using medlar fruit (Mespilus germanica L), which is grown in large amounts in Algeria. Experiments were performed using aqueous medium with fresh medlar. Prochiral heteroaryl ketones containing furan, thiophene, chroman, and thiochroman moieties were reduced with enantiomeric excess (ee) of up to 98%. High enantioselectivities have been observed especially for the bioreduction of tetralone 4 and thiochromanone 5 with ee of 89% and 98%, respectively. Bioreduction using different parts of medlar indicate that chromanone 6 was reduced with good asymmetric inductions 77% ee 85% whichever part of fruit was employed (whole, flesh, or juice) and medlar juice exhibited the best activity.
New developments in zinc-catalyzed asymmetric hydrosilylation of ketones with PMHS
Bette, Virginie,Mortreux, André,Savoia, Diego,Carpentier, Jean-Fran?ois
, p. 2837 - 2842 (2004)
The influence of structural modifications of the diamine ligand and the ZnR2 precursor in the [ZnR2-diamine]-catalyzed asymmetric hydrosilylation of prochiral ketones with PMHS in aprotic medium is reported. A new diamine ligand giving up to 91% ee in the reduction of acetophenone is described. The scope of this reduction system has been investigated using variously functionalized ketones and some deactivation pathways have been identified.
Candida viswanathii as a novel biocatalyst for stereoselective reduction of heteroaryl methyl ketones: A highly efficient enantioselective synthesis of (S)-α-(3-pyridyl)ethanol
Soni, Pankaj,Kaur, Gurmeet,Chakraborti, Asit K.,Banerjee, Uttam C.
, p. 2425 - 2428 (2005)
The enantioselective reduction of various heteroaryl methyl ketones, such as 2-, 3-, and 4-acetyl pyridines, 2-acetyl thiophene, 2-acetyl furan, and 2-acetyl pyrrole, was carried out with the resting cells of a novel yeast strain Candida viswanathii. Excellent results were obtained with acetyl pyridines. Moderate conversion took place with 2-acetyl thiophene, but no significant reduction was observed with 2-acetyl furan and 2-acetyl pyrrole. In the case of acetyl pyridines, the bioreduction was found to be sensitive toward the nature of substitution on the pyridine nucleus and the conversion followed the order 4-acetyl pyridine > 3-acetyl pyridine > 2-acetyl pyridine. Reduction of 3-acetyl pyridine with a high conversion (>98%) and excellent enantioselectivity (ee >99%) provided the biocatalytic preparation of (S)-α-(3-pyridyl)ethanol, a key intermediate of pharmacologically interesting alkaloids-akuamidine and heteroyohimidine. Finally, preparative scale reduction of 3-acetyl pyridine has been carried out with excellent yield (>85%) and almost absolute enantioselectivity (ee >99.9%).
[Zinc-diamine]-catalyzed hydrosilylation of ketones in methanol. New developments and mechanistic insights
Bette, Virginie,Mortreux, Andre,Savoia, Diego,Carpentier, Jean-Francois
, p. 289 - 302 (2005)
The Zn-promoted direct reduction of various ketones, including alkyl aryl ketones, α- and β-keto esters, α- and β-keto amides, into the corresponding alcohols with polymethylhydrosiloxane (PMHS) in protic conditions is reported. The reaction proceeds chemoselectively under smooth conditions, with simple catalyst combinations based on a zinc precursor [ZnEt2, Zn(OMe)2, Zn(OH)2] and a 1,2-diamine ligand, e.g., N,N′-dibenzylethylenediamine (dbea). The reaction rates are significantly faster than under aprotic conditions. For β-keto esters and amides, the use of an excess of PMHS is required. Moderate enantioselectivities (ee up to 55%) have been obtained using a variety of enantiopure diamine ligands. Two mechanisms are proposed for the new catalytic reaction, on the basis of the synthesis of [(diamine)Zn(alkoxide)2] complexes which are models of the possible reaction intermediates and a study of their activity.
Asymmetric aerobic oxidation of secondary alcohols catalyzed by poly(: N-vinyl-2-pyrrolidone)-stabilized gold clusters modified with cyclodextrin derivatives
Hirano, Koto,Takano, Shinjiro,Tsukuda, Tatsuya
, p. 15033 - 15036 (2019)
Surface modification of poly(N-vinyl-2-pyrrolidone)-stabilized gold clusters (1.8 ± 0.6 nm) with aminated cyclodextrins induced aerobic oxidative kinetic resolution of racemic secondary alcohols (krel = 1.2).
Practical access to (S)-heterocyclic aromatic acetates via CAL-B/Na2CO3-deacylation and Mitsunobu reaction protocol
Aribi-Zouioueche, Louisa,Bra?a, Nabila,Merabet-Khelassi, Mounia,Toffano, Martial
, (2022/02/11)
Herein, we report the preparation of enantiomerically pure forms of 2,3-dihydrobenzofuran-3-ol (1), chroman-4-ol (2), thiochroman-4-ol (3), 1-(furan-2-yl) ethanol (5) and 1-(thiophen-2-yl) ethanol (6), through a kinetic resolution catalysed by Candida antarctica lipase B/Na2CO3 hydrolysis sequence in organic media. The (R)-furnished alcohols and the (S)-remained acetates are recovered enantiopures (ee?>99%, E???200, Conv = 50%). Those ideal enzymatic kinetic resolution (EKRs) are well incorporated to the Mitsunobu inversion protocol in a one pot procedure to give (S)-heterocyclic acetates (1a–3a) in good to high enantiomeric excess (88%–92% ee). Whilst, the (S)-heteroaromatic acetates (5a and 6a) are given with moderate enantiomeric excess (51%–62% ee). All the (S)-acetates are given in good isolated chemical yields (>80%) allowing to overcome the maximum of 50% yield which could be usually reached in a regular kinetic resolution processes.
Cinchona-Alkaloid-Derived NNP Ligand for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones
Chen, Qian,Jiang, Jian,Li, Chun,Li, Linlin,Sun, Hao,Yang, Yuanyong,Zhang, Lin,Zhang, Ling,Zhao, Chong
supporting information, (2022/01/12)
Most ligands applied for asymmetric hydrogenation are synthesized via multistep reactions with expensive chemical reagents. Herein, a series of novel and easily accessed cinchona-alkaloid-based NNP ligands have been developed in two steps. By combining [Ir(COD)Cl]2, 39 ketones including aromatic, heteroaryl, and alkyl ketones have been hydrogenated, all affording valuable chiral alcohols with 96.0-99.9% ee. A plausible reaction mechanism was discussed by NMR, HRMS, and DFT, and an activating model involving trihydride was verified.
Dynamic Kinetic Resolution of Alcohols by Enantioselective Silylation Enabled by Two Orthogonal Transition-Metal Catalysts
Oestreich, Martin,Seliger, Jan
, p. 247 - 251 (2020/10/29)
A nonenzymatic dynamic kinetic resolution of acyclic and cyclic benzylic alcohols is reported. The approach merges rapid transition-metal-catalyzed alcohol racemization and enantioselective Cu-H-catalyzed dehydrogenative Si-O coupling of alcohols and hydrosilanes. The catalytic processes are orthogonal, and the racemization catalyst does not promote any background reactions such as the racemization of the silyl ether and its unselective formation. Often-used ruthenium half-sandwich complexes are not suitable but a bifunctional ruthenium pincer complex perfectly fulfills this purpose. By this, enantioselective silylation of racemic alcohol mixtures is achieved in high yields and with good levels of enantioselection.
