56409-75-7Relevant articles and documents
Catalytic asymmetric construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements
Qu, Jingping,Wang, Baomin,Wang, Wenyao,Wei, Shiqiang,Zhang, Wande
supporting information, p. 6550 - 6553 (2021/07/07)
An organocatalytic asymmetric process was reported for the sterically precise construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements. A series of interesting products featuring the union of a centrally chiral pyrazolone moiety and an axially chiral styrene unit were obtained in high yield with excellent diastereoselectivity and enantioselectivity (up to 99% ee, >20?:?1 dr). The process has the characteristics of mild reaction conditions, simple operation and broad substrate scope. The result of gram-scale reaction indicates that the reaction has good practicability.
Catalyst-controlled regiodivergent 1,2-difunctionalization of alkenes with two carbon-based electrophiles
Belal, Md.,Li, Zheqi,Yin, Guoyin,Zhu, Lei
, (2021/12/24)
Regiodivergent catalysis provides an efficient strategic approach for the construction of architecturally different molecules from the same starting materials. In this field, the intermolecular regiodivergent 1,2-difunctionalization of alkenes with two electrophiles is still a challenging task. A ligand-controlled, nickel-catalyzed regiodivergent dicarbofunctionalization of alkenes using both aryl/vinyl halides and acetals as electrophiles under mild reductive reaction conditions has been accomplished. This study provides a general approach to accessing both β-methoxyl esters and γ-methoxyl esters from readily available acrylates, aryl halides and acetals. Experimental mechanistic evidence supports that the difference in regioselective outcomes is attributed to the ligand tuning the reactivity of the nickel catalyst, which results in different catalytic cycles operating for these two reaction conditions.
Neutral-eosin Y-catalyzed regioselective hydroacylation of aryl alkenes under visible-light irradiation
Liu, Haiwang,Xue, Fei,Wang, Mu,Tang, Xinxin,Wu, Jie
supporting information, p. 406 - 410 (2020/12/30)
Styrene derivatives were hydroacylated with exclusive anti-Markovnikov selectivity by using neutral eosin Y as a direct hydrogen-atom-transfer (HAT) catalyst under visible-light irradiation. Aldehydes and styrenes with various substituents were tolerated (>20 examples), giving the corresponding products in moderate to high yields. The key acyl radical intermediate was generated from a direct HAT process induced by photoexcited eosin Y. Subsequent addition to styrenes and a reverse HAT process generated the ketone products.
REDUCTION METHOD AND REDUCTION PRODUCT OF ALKENYL ACTIVE METHYLENE COMPOUND
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Paragraph 0019-0020, (2021/07/02)
Disclosed are a reduction method and reduction product of an alkenyl active methylene compound. The reduction reaction comprises the following steps: taking an alkenyl active methylene compound as a substrate, a metal hydride as a reducing agent, and a palladium compound as a catalyst, performing a reduction reaction to obtain a reduction product, and then reducing the alkenyl active methylene compound. The reduction system is a simple method for reducing the alkenyl active methylene compound, and the used hydride and palladium compound catalyst are both reagents that could easily be obtained in a laboratory. Compared with conventional hydrogen hydrogenation methods and reduction methods of reducing agents, the method is easier to operate, higher in safety, mild in conditions, and high in reaction yield, a reaction in a one-pot two-step manner can be achieved, and high atom economy and step economy can be obtained.
Development of coumarine derivatives as potent anti-filovirus entry inhibitors targeting viral glycoprotein
Gao, Yinyi,Cheng, Han,Khan, Sameer,Xiao, Gaokeng,Rong, Lijun,Bai, Chuan
, (2020/07/23)
Filoviruses, including Ebolavirus (EBOV), Marburgvirus (MARV) and Cuevavirus, cause hemorrhagic fevers in humans with up to 90% mortality rates. In the 2014–2016 West Africa Ebola epidemic, there are 15,261 laboratory confirmed cases and 11,325 total deaths. The lack of effective vaccines and medicines for the prevention and treatment of filovirus infection in humans stresses the urgency to develop antiviral therapeutics against filovirus-associated diseases. Our previous study identified a histamine receptor antagonist compound CP19 as an entry inhibitor against both EBOV and MARV. The preliminary structure-activity relationship (SAR) studies of CP19 showed that its piperidine, coumarin and linker were related with its antiviral activities. In this study, we performed detailed SAR studies on these groups with synthesized CP19 derivatives. We discovered that 1) the piperidine group could be optimized with heterocycles, 2) the substitution groups of C3 and C4 of coumarin should be relatively large hydrophobic groups and 3) the linker part should be least substituted. Based on the SAR analysis, we synthesized compound 32 as a potent entry inhibitor of EBOV and MARV (IC50 = 0.5 μM for EBOV and 1.5 μM for MARV). The mutation studies of Ebola glycoprotein and molecular docking studies showed that the coumarin and its substituted groups of compound 32 bind to the pocket of Ebola glycoprotein in a similar way to the published entry inhibitor compound 118a. However, the carboxamide group of compound 32 does not have strong interaction with N61 as compound 118a does. The coumarin skeleton structure and the binding model of compound 32 elucidated by this study could be utilized to guide further design and optimization of entry inhibitors targeting the filovirus glycoproteins.
Complementing Pyridine-2,6-bis(oxazoline) with Cyclometalated N-Heterocyclic Carbene for Asymmetric Ruthenium Catalysis
Li, Long,Han, Feng,Nie, Xin,Hong, Yubiao,Ivlev, Sergei,Meggers, Eric
supporting information, p. 12392 - 12395 (2020/06/10)
A strategy for expanding the utility of chiral pyridine-2,6-bis(oxazoline) (pybox) ligands for asymmetric transition metal catalysis is introduced by adding a bidentate ligand to modulate the electronic properties and asymmetric induction. Specifically, a ruthenium(II) pybox fragment is combined with a cyclometalated N-heterocyclic carbene (NHC) ligand to generate catalysts for enantioselective transition metal nitrenoid chemistry, including ring contraction to chiral 2H-azirines (up to 97 % ee with 2000 TON) and enantioselective C(sp3)?H aminations (up to 97 % ee with 50 TON).
Environmentally benign nucleophilic substitution reaction of arylalkyl halides in water using CTAB as the inverse phase transfer catalyst
Godha, Atul K.,Thiruvengadam, Jayaraman,Abhilash, Viswanadhan,Balgi, Prajwal,Narayanareddy,Vignesh, Kumaresan,Gadakh, Amol V.,Sathiyanarayanan,Ganesh, Sambasivam
supporting information, p. 16041 - 16045 (2019/10/28)
An environmentally benign, practically scalable and highly selective C-arylalkylation of active methylene compounds is developed using CTAB as the inverse phase transfer catalyst in water. The methodology developed is elaborated into the one-pot synthesis of quinoline derivatives and also applicable to the regioselective N-aralkyl of 2-pyridones.
Highly Carbon-Selective Monofluoromethylation of β-Ketoesters with Fluoromethyl Iodide
Ding, Tianqi,Jiang, Lvqi,Yang, Jie,Xu, Yimin,Wang, Guixiang,Yi, Wenbin
supporting information, p. 6025 - 6028 (2019/08/20)
A highly carbon-selective monofluoromethylation of a broad range of β-ketoesters with fluoromethyl iodide under mild conditions is described. The uses of lithium tert-butoxide as the base and diglyme as the solvent made great contributions to the high C/O regioselectivity.
Method for synthesizing beta-keto ester through copper catalysis
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Paragraph 0022-0024, (2019/12/02)
The invention relates to a method for synthesizing beta-keto ester by copper catalysis, which comprises the following steps of dissolving ethyl acylacetate and halogenated hydrocarbon in an organic solvent, adding a copper catalyst and alkali, reacting at 60-90 DEG C for 12-18 hours, and separating and purifying to obtain the beta-keto ester. Compared with the prior art, the method has the advantages of simple and green synthesis process, excellent selectivity, higher yield and wide substrate range, and has the wide application value in the fields of biology, pharmaceutical chemistry industryand the like.
Carbocation Lewis Acid TrBF4-Catalyzed 1,2-Hydride Migration: Approaches to (Z)-α,β-Unsaturated Esters and α-Branched β-Ketocarbonyls
Duan, Depeng,Liu, Yongjun,Lv, Jian,Shang, Wansong
supporting information, (2019/10/08)
Carbocation Lewis acid TrBF4-catalyzed 1,2-hydride migration of α-alkyldiazoacetates themselves or in situ-generated cross-coupling adducts of aldehydes and α-alkyldiazoacetates has been developed, affording (Z)-α,β-unsaturated esters and α-branched β-ketocarbonyls, respectively, in good yields and with high regioselectivities.
