- Synthesis of Cyclopentenones through Rhodium-Catalyzed C-H Annulation of Acrylic Acids with Formaldehyde and Malonates
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An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C-H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution. Excess formaldehyde and malonate led to a multicomponent reaction that afforded the multisubstituted cyclopentenones through a Michael addition.
- Yu, Shuling,Hong, Chao,Liu, Zhanxiang,Zhang, Yuhong
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supporting information
p. 5054 - 5059
(2021/07/20)
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- Macrolactam Synthesis via Ring-Closing Alkene-Alkene Cross-Coupling Reactions
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Reported herein is a practical method for macrolactam synthesis via a Rh(III)-catalyzed ring closing alkene-alkene cross-coupling reaction. The reaction proceeded via a Rh-catalyzed alkenyl sp2 C-H activation process, which allows access to macrocyclic molecules of different ring sizes. Macrolactams containing a conjugated diene framework could be easily prepared in high chemoselectivities and Z,E stereoselectivities.
- Goh, Jeffrey,Loh, Teck-Peng,Maraswami, Manikantha
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supporting information
p. 9724 - 9728
(2020/12/21)
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- SULFONYL-SUBSTITUTED BICYCLIC COMPOUND WHICH ACTS AS ROR INHIBITOR
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Provided is a sulfonyl-substituted bicyclic compound (A) which acts as a RORγ inhibitor, said compound has good RORγ inhibitory activity and is expected to be used for treating diseases mediated by a RORγ receptor in mammals.
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Paragraph 0325; 0326
(2020/08/16)
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- Exploring the Promiscuous Enzymatic Activation of Unnatural Polyketide Extender Units in Vitro and in Vivo for Monensin Biosynthesis
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The incorporation of new-to-nature extender units into polyketide synthesis is an important source for diversity yet is restricted by limited availability of suitably activated building blocks in vivo. We here describe a straightforward workflow for the biogenic activation of commercially available new-to-nature extender units. Firstly, the substrate scope of a highly flexible malonyl co-enzyme A synthetase from Streptomyces cinnamonensis was characterized. The results were matched by in vivo experiments in which the said extender units were accepted by both the polyketide synthase and the accessory enzymes of the monensin biosynthetic pathway. The experiments gave rise to a series of predictable monensin derivatives by the exploitation of the innate substrate promiscuity of an acyltransferase and downstream enzyme functions.
- Grote, Marius,Schulz, Frank
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p. 1183 - 1189
(2019/03/11)
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- Copper-catalyzed intermolecular chloro- and bromotrifluoromethylation of alkenes
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A highly practical copper-catalyzed intermolecular halotrifluoromethylation of alkenes has been developed under mild reaction conditions. A variety of Cl/Br-containing trifluoromethyl derivatives were directly synthesized from a wide range of alkenes, including electron-deficient and unactivated alkenes.
- Fu, Mingyang,Chen, Long,Jiang, Yongpeng,Jiang, Zhong-Xing,Yang, Zhigang
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supporting information
p. 348 - 351
(2016/02/19)
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- Bifunctional Iminophosphorane Catalyzed Enantioselective Sulfa-Michael Addition to Unactivated α-Substituted Acrylate Esters
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The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated α-substituted acrylate esters catalyzed by a bifunctional iminophosphorane organocatalyst under mild conditions is described. The strong Br?nsted basicity of the iminophosphorane moiety of the catalyst provides the necessary activation of the alkyl thiol pro-nucleophile, while the two tert-leucine residues flanking a central thiourea hydrogen-bond donor facilitate high enantiofacial selectivity in the protonation of the transient enolate intermediate. The reaction is broad in scope with respect to the alkyl thiol, the ester moiety, and the α-substituent of the α,β-unsaturated ester, affords sulfa-Michael adducts in excellent yields (up to >99%) and enantioselectivities (up to 96% ee), and is amenable to decagram scale-up using catalyst loadings as low as 0.05 mol %.
- Farley, Alistair J. M.,Sandford, Christopher,Dixon, Darren J.
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supporting information
p. 15992 - 15995
(2016/01/15)
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- Expanding the utility of Bronsted base catalysis: Biomimetic enantioselective decarboxylative reactions
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As a result of the low reactivity of simple esters, the use of them as nucleophiles in direct asymmetric transformations is a long-standing challenge in synthetic organic chemistry. Nature approaches this difficulty through a decarboxylative mechanism, which is used for polyketide synthesis. Inspired by nature, we report guanidine-catalyzed biomimetic decarboxylative C-C and C-N bond-formation reactions. These highly enantioselective decarboxylative Mannich and amination reactions utilized malonic acid half thioesters as simple ester surrogates. It is proposed that nucleophilic addition precedes decarboxylation in the mechanism, which has been investigated in detail through the identification of intermediates by using electrospray ionization (ESI) mass-spectrometric analysis and DFT calculations. Copyright
- Pan, Yuanhang,Kee, Choon Wee,Jiang, Zhiyong,Ma, Ting,Zhao, Yujun,Yang, Yuanyong,Xue, Hansong,Tan, Choon-Hong
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supporting information; experimental part
p. 8363 - 8370
(2011/09/13)
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- Anti-ischemic compounds
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The present invention is related to a compound of formula (I), salts and pro-drugs of the compound (I) and methods for treating and/or preventing partial or total ischemia, methods for treating and/or preventing pathologies associated with ischemia or with mitochondrial deficiencies.
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- Synthesis and evaluation of α,α -disubstituted-3-mercaptopropanoic acids as inhibitors for carboxypeptidase A and implications with respect to enzyme inhibitor design
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2-Ethyl-2-methyl-3-mercaptopropanoic acid (6) and 2-benzyl-2-methyl-3-mercaptopropanoic acid (7) were synthesized and evaluated as inhibitors for carboxypeptidase A (CPA), a prototypical zinc protease with the expectation that the binding affinities of these inhibitors would be augmented over those of 2-ethyl-3-methylsuccinic acid (2) and 2-benzyl-3-methylsuccinic acid (3), respectively, in light of the fact that the sulfhydryl group is a better zinc coordinating moiety than the carboxylate group. Contrary to the expectation, however, the inhibitory potency of 6 was not improved and that of 7 was rather attenuated by the replacement. A probable explanation for the unexpected results is offered.
- Lee, Hyun Soo,Kim, Dong H.
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p. 4685 - 4691
(2007/10/03)
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- Ligandgesteuerte Ringkontraktion von Nickela-Fuenf- in Vierringkomplexe-neuartige Startsysteme fuer die praeparative Chemie
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Nickela-compounds with a five-membered ring, 4, are formed on Ni0 from CO2 and alkenes in the presence of the heterodifunctional ligand (cyclo-C6H11)2PCH2-CH2-2-pyridyl (2).A ring contraction occurs on addition of a promotor, such as BeCl2 or on heating.The greater reactivity of the nickela-complex with a four-membered ring, 6, can be used in the former reactions with CO2, CO or CH2=CH2.Such a sequence of reactions can be employed for the catalytic reaction of ethene with acrylic anilide on a (C6H11)3P/Ni0 system.
- Hoberg, Heinz,Ballesteros, Alfredo,Sigan, Andrei,Jegat, Corine,Baerhausen, Dieter,Milchereit, Armin
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p. C23 - C29
(2007/10/02)
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- Aminobenzoic and aminocyclohexanecarboylic acid compounds, compositions, and their method of use
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Compounds of the formula inhibit the action of neutral endopeptidase. As a result, such compounds produce diuresis, natriuresis, and lower blood pressure as well as being useful in the treatment of congestive heart failure, relieving pain, and diarrhea when administered to a mammalian host.
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- 1,1-Alkanediol dicarboxylate linked antibacterial agents
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Useful antibacterial agents in which a penicillin and/or a beta-lactamase inhibitor are linked via 1,1-alkanediol dicarboxylates are of the formula STR1 where A is the residue of certain dicarboxyic acids, R3 is H or (C1 -C3), n is zero or 1 such that when n is zero R is P or B and R1 is the residue of certain esters, H or a salt thereof; and when n is 1, one of R and R1 is P and the other is B, and P is STR2 where R2 is H or certain acyl groups, and B is the residue of a beta-lactamase inhibiting carboxylic acid; a method for their use, pharmaceutical compositions thereof and intermediates useful in their production.
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- Bis-esters of dicarboxylic acids with amoxicillin and certain hydroxymethylpenicillanate 1,1-dioxides
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Antibacterial bis-esters of 1,4-cyclohexanedicarboxylic acids and alkane dicarboxylic acids wherein the ester moieties are derived from different alcohols; one alcohol being hydroxymethylpenicillanate 1,1-dioxide, or the 6-beta-hydroxymethyl or the 6-alpha-aminomethyl derivative thereof; and the other being 6-[D-(2-amino-2-(p-hydroxyphenyl)acetamido)]penicillanic acid (amoxicillin); and pharmaceutically acceptable salts thereof; a method for the use of said esters and their salts, and methods for their preparation.
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- Hydrogenolysis of Small Cycloalkanes, VII. Selective Hydrogenation of 1,1-Disubstituted Cyclopropane Derivatives
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On hydrogenation of 1,1-disubstituted cyclopropane derivatives 1 hydrogenolysis of the C-2-C-3 bond to yield 2 is promoted by electron releasing groups (R =alkyl, CH2OH, OR).On the other hand the presence of electron attracting substituents (R = CO2R, COR, CN) causes opening of the C-1-C-2 bond and formation of products 3. 1,1-Bis(trifluoromethyl)cyclopropane could not be hydrogenated.
- Groeger, Claus,Musso, Hans,Rossnagel, Ingrid
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p. 3621 - 3628
(2007/10/02)
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