6249-79-2Relevant articles and documents
Stereodivergent Access to Enantioenriched Epoxy Alcohols with Three Stereogenic Centers via Ruthenium-Catalyzed Transfer Hydrogenation
Zhao, Zhifei,Bagdi, Prasanta Ray,Yang, Shuang,Liu, Jinggong,Xu, Weici,Fang, Xinqiang
supporting information, p. 5491 - 5494 (2019/08/01)
The resolution technique of stereodivergent reaction on racemic mixtures (stereodivergent RRM) was employed for the first time in ruthenium complex catalyzed transfer hydrogenation of racemic epoxy ketones, providing a new and very simple method that allows access to enantioenriched epoxy alcohols with three stereogenic centers in a one-step fashion. The protocol features simple reaction conditions, practical operation, ability to scale up, and broad group tolerance.
An efficient Darzens reaction promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)
Luo, Juan,Hu, Lanfang,Zhang, Minghao,Tang
supporting information, p. 1949 - 1951 (2019/07/03)
An efficient DBU promoted Darzens reaction utilising α-haloketones containing an enolizable α′-hydrogen is reported. This method diastereoselectively afforded the corresponding α,β-epoxy ketones good to excellent yields in an one-pot reaction without using any transition metals or additives. Furthermore, haloketones without an α′-hydrogen are also applicable in this reaction.
Preparation method of alpha, beta-epoxy ketone compound
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Paragraph 0036-0039, (2019/07/29)
The invention provides a method for efficiently preparing an alpha, beta-epoxy ketone compound from alpha-hydrogen-containing alpha-halogenated ketone as a raw material and various aldehydes under theaction of DBU or DBN. Namely the method comprises the steps: slowly and dropwise adding a dichloromethane mixed solution of alpha-halogenated ketone and aldehydes into a dichloromethane solution of DBU or DBN under the conditions of inert gas shielding and 20 DEG C below zero, ending a reaction, and then, carrying out separation and purification to obtain the alpha, beta-epoxy ketone compound. The synthesis method provided by the invention is available in raw material, low in cost, simple and easily-controlled in operation, relatively few in side reactions, simple in aftertreatment, relatively high in product yield, capable of greatly reducing the production cost, relatively high in economic benefit and suitable for large-scale industrial production.
Arylruthenium(III) Porphyrin-Catalyzed C-H Oxidation and Epoxidation at Room Temperature and [RuV(Por)(O)(Ph)] Intermediate by Spectroscopic Analysis and Density Functional Theory Calculations
Shing, Ka-Pan,Cao, Bei,Liu, Yungen,Lee, Hung Kay,Li, Ming-De,Phillips, David Lee,Chang, Xiao-Yong,Che, Chi-Ming
supporting information, p. 7032 - 7042 (2018/06/12)
The development of highly active and selective metal catalysts for efficient oxidation of hydrocarbons and identification of the reactive intermediates in the oxidation catalysis are long-standing challenges. In the rapid hydrocarbon oxidation catalyzed by ruthenium(IV) and -(III) porphyrins, the putative Ru(V)-oxo intermediates remain elusive. Herein we report that arylruthenium(III) porphyrins are highly active catalysts for hydrocarbon oxidation. Using catalyst [RuIII(TDCPP)(Ph)(OEt2)] (H2TDCPP = 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin), the oxidation of C-H bonds of various hydrocarbons with oxidant m-CPBA at room temperature gave alcohols/ketones in up to 99% yield within 1 h; use of [nBu4N]IO4 as a mild alternative oxidant avoided formation of lactone from cyclic ketone in C-H oxidation, and the catalytic epoxidation with up to 99% yield and high selectivity (no aldehydes as side product) was accomplished within 5 min. UV-vis, electrospray ionization-mass spectrometry, resonance Raman, electron paramagnetic resonance, and kinetic measurements and density functional theory calculations lend evidence for the formation of Ru(V)-oxo intermediate [RuV(TDCPP)(O)(Ph)].
Biomimetic Oxidative Deamination Catalysis via ortho-Naphthoquinone-Catalyzed Aerobic Oxidation Strategy
Golime, Gangadhararao,Bogonda, Ganganna,Kim, Hun Young,Oh, Kyungsoo
, p. 4986 - 4990 (2018/05/14)
An ortho-naphthoquinone-catalyzed oxidative deamination reaction has been developed where the molecular oxygen and water serve as the sole oxidant and nucleophile. The current aerobic deamination reaction proceeds via the ketimine formation between ortho-naphthoquinones and amines followed by the prototropic rearrangement and hydrolysis by water, representing a biomimetic oxidative deamination of amine species in the human body by the liver and kidneys. The compatibility of ortho-naphthoquinone organocatalysts with molecular oxygen and water opens up a new biomimetic catalyst system that can function as versatile deaminases for a variety of amine-containing molecules such as amino acids and DNA nuclear bases.
Evidence of a Sole Oxygen Atom Transfer Agent in Asymmetric Epoxidations with Fe-pdp Catalysts
Cussó, Olaf,Serrano-Plana, Joan,Costas, Miquel
, p. 5046 - 5053 (2017/08/17)
Iron complexes with chiral tetradentate ligands based on the pdp scaffold (pdp = N,N′-bis(2-pyridylmethyl)-2,2′-bipyrrolidine) are efficient and versatile catalysts for the highly enantioselective epoxidation of a wide range of olefins. The nature of the
Preparation method and applications of parthenolide analogues
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Paragraph 0044; 0045; 0046; 0047; 0048, (2016/10/10)
The invention relates to a preparation method and applications of parthenolide analogues, and belongs to the field of organic synthesis. On the basis of reserving the main active group alpha-methylene-gamma-lactone and epoxide structure of parthenolide, series of compounds are designed by changing its framework, and its in-vitro antitumor activity is tested. Series of parthenolide analogues having biological activity are synthesized by a simple method, wherein two compounds are nontoxic to normal cells.
Metal-free, one-pot, sequential protocol for transforming ,-epoxy ketones to -hydroxy ketones and -methylene ketones
Hasegawa, Eietsu,Arai, Saki,Tayama, Eiji,Iwamoto, Hajime
, p. 1593 - 1600 (2015/02/19)
A new sequential, one-pot protocol for transforming 1,3-disubstituted 2,3-epoxy ketones to β;-hydroxy ketones and α-methylene ketones has been developed. Reaction of epoxy ketones with boron trifluoride etherate (BF3·OEt2) generates the cationic intermediates by regioselective epoxide ring opening and an acyl shift. Then, a treatment of these cations with 2-aryl-1,3-dimethylbenzimidazolines (DMBIH) results in formation of 1,2-disubstituted 3-hydroxy ketones. DMBIH serves as a hydride donor in the second step of this process. Finally, the β;-hydroxy ketones can be converted to 1,2-disubstituted 2-methylene ketones by treatment with methanesulfonic acid or a combination of methanesulfonyl chloride and triethylamine. Importantly, the sequential steps involved in formation of the α-methylene ketone products can be carried out in one pot.
Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41
Goldani, Mohammad Taghi,Mohammadi, Ali,Sandaroos, Reza
, p. 801 - 805 (2014/07/07)
A series of Fe(III) Schiff base complexes immobilized on MCM-41 were prepared and characterized by various physicochemical and spectroscopic methods. The complexes were used for oxidation of cyclohexene by 30% hydrogen peroxide in the presence and absence of ethylmethyl imidazolium chloride (EMIM) ionic liquid as solvent. The immobilized complexes proved to be effective catalysts and generally exhibited much higher catalytic performance than their homogeneous analogue. Catalytic performance of the complexes was also found to be closely related to the Schiff base ligands used. Additionally, ion liquid solvent efficiently improved all the catalytic performances. Finally, the reaction was extended to different alkenes using the heterogeneous complex 2-L4. Among all the alkenes, those containing π-electron-withdrawing groups and trans-orientations exhibited lower tendency for oxidation.
Highly enantioselective bioinspired epoxidation of electron-deficient olefins with H2O2 on aminopyridine mn catalysts
Ottenbacher, Roman V.,Samsonenko, Denis G.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
, p. 1599 - 1606 (2014/05/20)
The asymmetric epoxidation of various electron-deficient olefins with H2O2 in the presence of a novel family of chiral bioinspired bipyrrolidine-derived aminopyridine manganese(II) complexes [LM II(OTf)2] is rep
