101219-68-5Relevant articles and documents
Sugar-monophosphite ligands applied to the asymmetric Ni-catalyzed trialkylaluminum addition to aldehydes
Alegre, Sabina,Dieguez, Montserrat,Pmies, Oscar
, p. 834 - 839 (2011)
A series of readily available sugar-based phosphite ligands were applied to the Ni-catalyzed asymmetric trialkylaluminum additions to aldehydes. The ability of the catalysts to transfer chiral information to the product could be tuned by choosing suitable ligand components (configuration at C-3 of the furanoside backbone; the steric hindrance of the substituent at C-3 and the substituents/configuration of the biaryl phosphite moieties). Good enantioselectivities (ee's up to 84%) were obtained for several aryl aldehydes using several organoaluminum sources.
Efficient resolution of prostereogenic arylaliphatic ketones using a recombinant alcohol dehydrogenase from Pseudomonas fluorescens
Hildebrandt, Petra,Riermeier, Thomas,Altenbuchner, Josef,Bornscheuer, Uwe T.
, p. 1207 - 1210 (2001)
A broad range of arylaliphatic ketones is efficiently reduced to the corresponding optically active (R)-alcohols by a recombinant alcohol dehydrogenase from Pseudomonas fluorescens (PFADH) produced by overexpression in Escherichia coli. PFADH shows high activity and stereoselectivity in the reduction of acetophenone and various derivatives (45-99% e.e.), as well as in the reduction of 3-oxobutyric acid methyl ester (>99% e.e.). The highest activity was observed between 10 and 20°C. The cofactor NADH can be efficiently recycled by the addition of 10-20% (v/v) of iso-propanol.
Synthesis and biological evaluation of disubstituted pyrimidines as selective 5-HT2C agonists
Kim, Juhyeon,Kim, Yoon Jung,Londhe, Ashwini M.,Pae, Ae Nim,Choo, Hyunah,Kim, Hak Joong,Min, Sun-Joon
, (2019)
Here, we describe the synthesis of disubstituted pyrimidine derivatives and their biological evaluation as selective 5-HT2C agonists. To improve selectivity for 5-HT2C over other subtypes, we synthesized two series of disubstituted pyrimidines with fluorophenylalkoxy groups at either the 5-position or 4-position and varying cyclic amines at the 2-position. The in vitro cell-based assay and binding assay identified compounds 10a and 10f as potent 5-HT2C agonists. Further studies on selectivity to 5-HT subtypes and drug-like properties indicated that 2,4-disubstituted pyrimidine 10a showed a highly agonistic effect on the 5-HT2C receptor, with excellent selectivity, as well as exceptional drug-like properties, including high plasma and microsomal stability, along with low CYP inhibition. Thus, pyrimidine 10a could be considered a viable lead compound as a 5-HT2C selective agonist.
Enantioselective reduction of 4-fluoroacetophenone at high substrate concentration using a tailor-made recombinant whole-cell catalyst
Groeger, Harald,Rollmann, Claudia,Chamouleau, Francoise,Sebastien, Isabelle,May, Oliver,Wienand, Wolfgang,Drauz, Karlheinz
, p. 709 - 712 (2007)
A practical and highly efficient biocatalytic synthesis of optically active (R)-4-fluorophenylethan-1-ol has been developed based on reduction of the corresponding 4-fluoroacetophenone in the presence of a tailor-made recombinant whole-cell biocatalyst, containing an alcohol dehydrogenase and a glucose dehydrogenase. The reaction proceeds in a pure aqueous solvent media at a substrate concentration of ca. 0.5 M, and gives the desired product with high conversion (>95%), good yield (87%) and with an excellent enantioselectivity of >99% ee. In addition, activity tests further showed that also the analogous 2- and 3-fluoroace-tophenones are promising substrates.
Cheap and environmentally sustainable stereoselective arylketones reduction by Lactobacillus reuteri whole cells
Perna,Ricci,Scilimati,Mena,Pisano,Palmieri,Agrimi,Vitale
, p. 29 - 37 (2016)
Various Lactobacillus reuteri strains were investigated as whole cell catalysts for the bioreduction of acetophenone into optically active (R)-1-phenylethanol. L. reuteri DSM 20016 strain gave an almost complete substrate conversion, in a short reaction time and enantiomeric excess up to 99%. The acetophenone bioreduction was used as a model reaction to optimize temperature and reducing equivalent source (glucose, lactose, cheese way and lignocellulosic hydrolysates) to accomplish the biotransformation. The reduction of acetophenones into optically active (R)-1-arylethanols was also exploited to study L. reuteri DSM 20016 substrate specificity. In most of the cases, optically active (R)-1-arylethanols have been obtained with both excellent chemical and optical yields and with (R)-enantiopreference, through a cheap, simple and efficient process.
Chiral Yolk-Shell MOF as an Efficient Nanoreactor for Asymmetric Catalysis in Organic-Aqueous Two-Phase System
Shi, Shunli,Zhong, Yicheng,Hu, Zhuo,Wang, Lei,Yuan, Mingwei,Ding, Shunmin,Wang, Shuhua,Chen, Chao
, p. 12714 - 12718 (2021)
It remains a great challenge to introduce large and efficient homogeneous asymmetric catalysts into MOFs and other microporous materials as well as retain their degrees of freedom. Herein, a new heterogeneous strategy of homogeneous chiral catalysts is proposed, that is, to construct a yolk-shell MOFs-confined, large-size, and highly efficient homogeneous chiral catalyst, which can be used as a nanoreactor for asymmetric catalytic reactions.
Construction of a chiral macromolecular catalyst in hollow silica nanoreactors for efficient and recyclable asymmetric catalysis
Jing, Lingyan,Zhang, Xiaoming,Guan, Ruqun,Yang, Hengquan
, p. 2304 - 2311 (2018)
The entrapment method is a fascinating pathway to convert homogeneous into heterogeneous catalysts. However, the types of entrapped catalysts and available supports are still limited because of the strict requirements of this method. Here, we reported a novel strategy for achieving efficient entrapment of a chiral homogeneous catalyst by forming macromolecular polymers in the cavity of hollow silica nanoreactors. Specifically, through in situ polymerization of the chiral ligand (1R,2R)-N1-(4-vinylbenzenesulfonyl)-1,2-diphenylethane-1,2-diamine (VBS-DPEN) with styrene followed by coordination of the metal precursor [Cp?RhCl2]2 (Cp? = pentamethylcyclopentadiene), a chiral solid catalyst with a confined macromolecular polymer was obtained. In the aqueous asymmetric transfer hydrogenation (ATH) of ketones, such a catalyst exhibited much better activity (TOF 991 vs. 724 h-1) and similar enantioselectivity (94% ee) compared with its homogeneous counterpart. This excellent activity can be attributed to the combination of the hollow mesoporous structure, unique hydrophobic@hydrophilic surface properties and semi-free state of the macromolecular catalyst. Moreover, the solid catalyst exhibits good recyclability, which is much better than the pure macromolecular polymer catalyst. Our studies not only provide an excellent heterogeneous asymmetric catalyst but also demonstrate that the pathway for confining macromolecules could be used as an efficient scaffold for the synthesis of entrapped catalysts.
Screening of a modular sugar-based phosphoroamidite ligand library in the asymmetric nickel-catalyzed trialkylaluminium addition to aldehydes
Raluy, Eva,Dieguez, Montserrat,Pamies, Oscar
, p. 1575 - 1579 (2009)
A modular sugar-based phosphoroamidite ligand library for the Ni-catalyzed trialkylaluminium addition to aldehydes has been synthesized and screened. After systematic variation of the sugar backbone, the substituents at the phosphoroamidite moieties and the flexibility of the ligand backbone, the monophosphoroamidite ligand 3-amine-3-deoxy-1,2:5,6-di-O-isopropylidene-((3,3′-di-trimethylsilyl-1,1′-biphenyl-2,2′-diyl)phosphite)-α-d-glucofuranose 1d were found to be optimal. Activities were high and enantioselectivities were good (ees up to 78%) for several aryl aldehydes.
Construction of hydrogen-bonded ternary organic crystals derived from L -tartaric acid and their application to enantioseparation of secondary alcohols
Kodama, Koichi,Sekine, Eriko,Hirose, Takuji
, p. 11527 - 11534 (2011)
Ternary organic crystals consisting of an L-tartaric acid-derived dicarboxylic acid, a commercially available achiral diamine, and a chiral secondary alcohol have been developed and characterized by X-ray crystallography. 1D, 2D, and 3D hydrogen-bonded supramolecular networks were constructed, depending on the structure of the diamine used. Benzylic and aliphatic secondary alcohols were enantioselectively incorporated into the crystal and were successfully enantioseparated with up to 86 and 79 % enantiomeric excess (ee), respectively. Selective incorporation of one enantiomer of 2-butanol, which is a small chiral aliphatic alcohol, was achieved by the cooperative effects of hydrogen bonds, CH...π interactions, and van der Waals interactions between the guest and host molecules, with the aid of two water molecules. The high host potential of the binary supramolecular system is mainly attributed to the skewed conformation of two rigid aromatic groups of tartaric acid derivatives, which prevents dense packing of the molecules and enhances the formation of multicomponent inclusion crystals.
Highly efficient iridium catalysts based on C2-symmetric ferrocenyl phosphinite ligands for asymmetric transfer hydrogenations of aromatic ketones
Ak, Bünyamin,Aydemir, Murat,Durap, Feyyaz,Meri?, Nermin,Elma, Duygu,Baysal, Akin
, p. 1307 - 1313 (2015)
A series of chiral modular C2-symmetric ferrocenyl phosphinite ligands have been synthesized in good yields by using 1,1′-ferrocenedicarboxyaldehyde and various amino alcohols as starting materials, and applied in the iridium(III)-catalyzed asymmetric transfer hydrogenations of aromatic ketones to give the corresponding secondary alcohols with good enantioselectivities and reactivities using 2-propanol as the hydrogen source (up to 98% ee and 99% conversion). The substituents on the backbone of the ligands were found to have a significant effect on both the activity and enantiomeric excess. The structures of these complexes have been clarified by a combination of multinuclear NMR spectroscopy, IR spectroscopy, and elemental analysis.
