115510-91-3Relevant articles and documents
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.
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.
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%).
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).
Highly Active Cooperative Lewis Acid—Ammonium Salt Catalyst for the Enantioselective Hydroboration of Ketones
Titze, Marvin,Heitk?mper, Juliane,Junge, Thorsten,K?stner, Johannes,Peters, René
supporting information, p. 5544 - 5553 (2021/02/05)
Enantiopure secondary alcohols are fundamental high-value synthetic building blocks. One of the most attractive ways to get access to this compound class is the catalytic hydroboration. We describe a new concept for this reaction type that allowed for exceptional catalytic turnover numbers (up to 15 400), which were increased by around 1.5–3 orders of magnitude compared to the most active catalysts previously reported. In our concept an aprotic ammonium halide moiety cooperates with an oxophilic Lewis acid within the same catalyst molecule. Control experiments reveal that both catalytic centers are essential for the observed activity. Kinetic, spectroscopic and computational studies show that the hydride transfer is rate limiting and proceeds via a concerted mechanism, in which hydride at Boron is continuously displaced by iodide, reminiscent to an SN2 reaction. The catalyst, which is accessible in high yields in few steps, was found to be stable during catalysis, readily recyclable and could be reused 10 times still efficiently working.
Amino Acid-Functionalized Metal-Organic Frameworks for Asymmetric Base–Metal Catalysis
Newar, Rajashree,Akhtar, Naved,Antil, Neha,Kumar, Ajay,Shukla, Sakshi,Begum, Wahida,Manna, Kuntal
, p. 10964 - 10970 (2021/03/29)
We report a strategy to develop heterogeneous single-site enantioselective catalysts based on naturally occurring amino acids and earth-abundant metals for eco-friendly asymmetric catalysis. The grafting of amino acids within the pores of a metal-organic framework (MOF), followed by post-synthetic metalation with iron precursor, affords highly active and enantioselective (>99 % ee for 10 examples) catalysts for hydrosilylation and hydroboration of carbonyl compounds. Impressively, the MOF-Fe catalyst displayed high turnover numbers of up to 10 000 and was recycled and reused more than 15 times without diminishing the enantioselectivity. MOF-Fe displayed much higher activity and enantioselectivity than its homogeneous control catalyst, likely due to the formation of robust single-site catalyst in the MOF through site-isolation.
