14786-43-7Relevant academic research and scientific papers
Chiral phosphinites as efficient ligands for enantioselective Ru(II), Rh(I) and Ir(III)-catalyzed transfer hydrogenation reactions
Baysal, Ak?n,Elma Karaka?, Duygu,Meri?, Nermin,Ak, Bünyamin,Aydemir, Murat,Durap, Feyyaz
, p. 365 - 372 (2017)
Abstract: Metal-catalyzed enantioselective transfer reduction of ketones to enantiomerically enriched chiral alcohols has recently attracted attention. Therefore, a series of methyl alkyl or alkyl/aryl ketones have been reduced by using Ru(II), Rh(I) and Ir(III) catalysts based on C2-symmetric chiral ferrocenyl phosphinite ligands. The corresponding optically active secondary alcohols were obtained in excellent conversions and moderate-to-good enantioselectivities. The best results were obtained with an iridium catalyst, giving up to 98% conversion and 80% ee.
Synthesis of cis-1,2-diol-type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation
Kilic, Ahmet,Balci, Tu?ba Ersayan,Arslan, Nevin,Aydemir, Murat,Durap, Feyyaz,Okumu?, Veysi,Tekin, Recep
, (2020)
Two cis-1,2-diol-type chiral ligands (T1 and T2) and their tri-coordinated chiral dioxaborinane (T(1–2)B(1–2)) and four-coordinated chiral dioxaborinane adducts with 4-tert-butyl pyridine sustained by N → B dati
Enantioselective reduction of 4-phenyl-2-butanone to chiral 4-phenyl-2-butanol in glycerol modified Saccharomyces cerevisiae cell culture
Cheng, Cheanyeh,Nian, Yu-Chuan
, p. 141 - 146 (2016)
A model compound 4-phenyl-2-butanone was used for studying the effect of glycerol in yeast Saccharomyces cerevisiae catalyzed reaction culture on the enantioselectivity for producing R- and S-4-phenyl-2-butanol under various reaction conditions. As the volume percentage of glycerol in the cell culture was 10%, the reaction gave a best R-enantiomeric excess (e.e.) value of 72.3% and a yield of 86.4% at the reaction conditions: a substrate concentration of 10 μg mL-1, 25 °C, an initial medium pH 10.0 but without controlling the pH, and without aeration. As the volume percentage of glycerol in the cell culture was 30%, the reaction showed a best S-e.e. value of 96.0% and a yield of 19.0% at the reaction conditions: a substrate concentration of 100 μg mL-1, 34 °C, pH 7.0, and without aeration. Substrate inhibition was shown with this reaction.
Nucleophilic Substitution of Chiral Amine N,N-Ditosylderivatives
Oppedal, Hilde,Tveit, Inger Catherine,Fiksdahl, Anne
, p. 895 - 902 (1994)
The chiral transformation of the optically active amine 10 to the corresponding alcohol 2 with opposite configuration is reported.The transformation is carried out via an SN2 type reaction of the N,N-ditosylimide, -NTs2, by nucleophilic attack of the hydroxide, acetate or benzoate ion to give an inversion degree of 85-100percent. 0-34percent stereoselectivity was obtained in the corresponding chloride nucleophilic substitutions.Separation parameters for the chromatographic enantioseparations of the amines 10-12, the chlorides 4, 7, 9 and the alcohol 2 using a chemically bonded cyclodextrin GLC column are discussed.
Chemoselective asymmetric hydrogenation of a α, β-unsaturated carbonyl compounds to allylic alcohols catalysed by BF4- aminophosphine
Mashima, Kazushi,Akutagawa, Takeshi,Zhang, Xiaoyong,Takaya, Hidemasa,Taketomi, Takanao,et al.
, p. 213 - 222 (1992)
Assymmetric hydrogenation of (E)-4-phenyl-3-buten-2-one by use of BF4 and o-dimethylaminophenyldiphenylphosphine afforded (E)-4-phenyl-3-buten-2-ol in 97percent chemoselectivity and in 65percent enantiomeric excess.A mixed ligand iridium dihydride complex containing both BINAP and the aminophosphine ligand has been shown to be the catalytically active species.
Biocatalyst-artificial metalloenzyme cascade based on alcohol dehydrogenase
Morra, Simone,Pordea, Anca
, p. 7447 - 7454 (2018)
Chemo-enzymatic cascades of enzymes with transition metal catalysts can offer efficient synthetic strategies, but their development is challenging due to the incompatibility between proteins and transition metal complexes. Rhodium catalysts can be combined with alcohol dehydrogenases to regenerate nicotinamide cofactors using formate as the hydride donor. However, their use is limited, due to binding of the metals to residues on the enzyme surface, leading to mutual enzyme and catalyst inactivation. In this work, we replaced the zinc from Thermoanaerobacter brockii alcohol dehydrogenase (TbADH) with Rh(iii) catalysts possessing nitrogen donor ligands, by covalent conjugation to the active site cysteine, to create artificial metalloenzymes for NADP+ reduction. TbADH was used as protein scaffold for both alcohol synthesis and the recycling of the cofactor, by combination of the chemically modified species with the non-modified recombinant enzyme. Stability studies revealed that the incorporation of the catalysts into the TbADH pocket provided a shielding environment for the metal catalyst, resulting in increased stability of both the recycling catalyst and the ADH. The reduction of a representative ketone using this novel alcohol dehydrogenase-artificial formate dehydrogenase cascade yielded better conversions than in the presence of free metal catalyst.
Cooperative Catalysis of an Alcohol Dehydrogenase and Rhodium-Modified Periodic Mesoporous Organosilica
Himiyama, Tomoki,Waki, Minoru,Maegawa, Yoshifumi,Inagaki, Shinji
, p. 9150 - 9154 (2019)
The combined use of a metal-complex catalyst and an enzyme is attractive, but typically results in mutual inactivation. A rhodium (Rh) complex immobilized in a bipyridine-based periodic mesoporous organosilica (BPy-PMO) shows high catalytic activity during transfer hydrogenation, even in the presence of bovine serum albumin (BSA), while a homogeneous Rh complex exhibits reduced activity due to direct interaction with BSA. The use of a smaller protein or an amino acid revealed a clear size-sieving effect of the BPy-PMO that protected the Rh catalyst from direct interactions. A combination of Rh-immobilized BPy-PMO and an enzyme (horse liver alcohol dehydrogenase; HLADH) promoted sequential reactions involving the transfer hydrogenation of NAD+ to give NADH followed by the asymmetric hydrogenation of 4-phenyl-2-butanone with high enantioselectivity. The use of BPy-PMO as a support for metal complexes could be applied to other systems consisting of a metal-complex catalyst and an enzyme.
Arrangements of enantiopure and racemic ionic liquids at the liquid/air interface: The role of chirality on self-assembly and layering
Caporali,Chiappe,Ghilardi,Iuliano,Longhi,Margari,Pomelli
, p. 8053 - 8060 (2016)
Chiral ionic liquids (CILs) have been obtained in high yield using commercial propylene oxide or natural alcohols (citronellol and nopol) as building blocks. The self-assembly ability at the interface IL/air for some couples of enantiopure and racemic CILs was explored by angle resolved XPS.
A new P-chiral bisphosphine, 1,1'-bis[(t- butyl)methylphosphino]ferrocene, as an effective ligand in catalytic asymmetric hydrosilylation of simple ketones
Tsuruta, Hideyuki,Imamoto, Tsuneo
, p. 877 - 882 (1999)
The asymmetric hydrosilylation of simple ketones was catalyzed by a rhodium complex with a P-chiral bisphosphine, 1,1'-bis[(t- butyl)methylphosphino]ferrocene, to give optically active alcohols with enantiomeric excesses of up to 92%.
Highly active CpIr catalyst at low temperatures bearing an N-heterocyclic carbene ligand and a chelated primary benzylamine in transfer hydrogenation
Sabater, Sara,Baya, Miguel,Mata, Jose A.
, p. 6830 - 6839 (2014)
The synthesis of new Cp Ir complexes bearing an N-heterocyclic carbene ligand and a chelated primary benzylamine is described. The new complexes are chiral at metal and have a stereogenic carbon at the benzylamine ligand. The synthesis is diastereoselective, and the origin is thermodynamically controlled. The chiral complexes have been fully characterized. The catalytic results show that the complexes are very active in transfer hydrogenation: for example, acetophenone is reduced to 1-phenylethanol in 2 h at 50 °C using a catalyst loading of 1 mol %. More interestingly is that no base, apart from the required for catalyst activation, is needed in the process. The enantioselectivities obtained range from low to moderate, with a maximum of 58% ee in the case of 2'-methylacetophenone. Initial mechanistic studies by means of DFT calculations suggest that the mechanism is based on a direct hydrogen transfer via a highly ordered transition state centered at the iridium amido group. The calculations are in good agreement with the experimental data and support a concerted one-step mechanism process.
