Tag: M.W=200-250

Gourdet, Benoit published the artcileRhodium-catalyzed carbometalation of ynamides with organoboron reagents, Quality Control of 480438-56-0, the main research area is oxazolidinone alkynyl rhodium catalyst carbometalation; ynamide carbometalation stereoselective regioselective rhodium catalyst; enamide stereoselective regioselective preparation.

In the presence of catalytic [Rh(cod)(MeCN)2]BF4, ynamides undergo carbometalation with boronic acids, arylboronic esters, and triarylboroxines. These reactions enable the regio- and stereocontrolled synthesis of multisubstituted enamides. E.g., reaction of 3-(2-phenylethynyl)oxazolidin-2-one with 4-chlorophenylboronic acid gave 65% 3-[(E)-2-(4-chlorophenyl)-2-phenylvinyl]oxazolidin-2-one (I).

Tetrahedron published new progress about Addition reaction catalysts, regioselective. 480438-56-0 belongs to class chlorides-buliding-blocks, name is 3-Chloro-4-isopropoxyphenylboronic acid, and the molecular formula is C9H12BClO3, Quality Control of 480438-56-0.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Campanico, Andre published the artcileAzaaurones as potent antimycobacterial agents active against MDR- and XDR-TB, Product Details of C13H9ClO2, the main research area is azaaurone antimycobacterial MDR XDR Mycobacterium tuberculosis; Mycobacterium tuberculosis; azaaurones; drug discovery; multidrug-resistant tuberculosis.

Herein we report the screening of a small library of aurones and their isosteric counterparts, azaaurones and N-acetylazaaurones, against Mycobacterium tuberculosis. Aurones were found to be inactive at 20 μM, whereas azaaurones and N-acetylazaaurones emerged as the most potent compounds, with nine derivatives displaying MIC99 values ranging from 0.4 to 2.0 μM. In addition, several N-acetylazaaurones were found to be active against multidrug-resistant (MDR) and extensively drug-resistant (XDR) clin. M. tuberculosis isolates. The antimycobacterial mechanism of action of these compounds remains to be determined; however, a preliminary mechanistic study confirmed that they do not inhibit the mycobacterial cytochrome bc1 complex. Addnl., microsomal metabolic stability and metabolite identification studies revealed that N-acetylazaaurones are deacetylated to their azaaurone counterparts. Overall, these results demonstrate that azaaurones and their N-acetyl counterparts represent a new entry in the toolbox of chemotypes capable of inhibiting M. tuberculosis growth.

ChemMedChem published new progress about Antibacterial agent resistance (overcoming). 61343-99-5 belongs to class chlorides-buliding-blocks, name is 4-(4-Chlorophenoxy)benzaldehyde, and the molecular formula is C13H9ClO2, Product Details of C13H9ClO2.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Gu, Jiali published the artcileThe role of aromatic residue W20 in the activity and enantioselectivity control of esterase BioH toward aryl substrate, Product Details of C9H9ClO3, the main research area is Escherichia esterase BioH enantioselectivity aryl substrate methyl chloromandelate; esterase BioH tryptophan phenylalanine aryl substrate pi pi stacking.

Aromatic π-π stacking interaction plays an important role in the enzyme-ligand recognition and stabilization. Esterase BioH, an α/β hydrolase from Escherichia coli, has exhibited potential in the chiral synthesis of alcs. and aryl prochiral diesters. In the present work, the influence of aromatic residue W20 on the activity and enantioselectivity of BioH toward aryl substrates was investigated. Mutation of Trp into Ala or Val led to complete loss of activity, while replacement of Trp by Phe had little effect on the activity and enantioselectivity. Structural and energetic anal. demonstrated that π-π stacking interactions were formed between the residue W20 and the substrate, as well as the residues W20 and F141, which facilitated the stabilization of substrate at the transition state. Moreover, the different probabilities of the parallel-shifted stacking interaction between the residue 20 and R-/S-enantiomer were found related to the enantioselectivity. Thus, it could be concluded that the π-π stacking interaction between the residue W20 and the substrate was crucial in the determination of enzymic catalytic performance. The results not only deepened our understanding in the catalytic mechanism of BioH, but also facilitated further enzyme redesign.

Biochemical Engineering Journal published new progress about Binding energy (BioH – aryl substrate). 32345-60-1 belongs to class chlorides-buliding-blocks, name is (S)-Methyl 2-(2-chlorophenyl)-2-hydroxyacetate, and the molecular formula is C9H9ClO3, Product Details of C9H9ClO3.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Poelloth, Benjamin published the artcileThe Size-Accelerated Kinetic Resolution of Secondary Alcohols, Application of Pyrene-2-carboxylic acid, the main research area is secondary alc kinetic resolution acylation side chain size enantioselectivity; acylation; asymmetric catalysis; kinetic resolution; molecular recognition; noncovalent interactions.

The factors responsible for the kinetic resolution of alcs. by chiral pyridine derivatives have been elucidated by measurements of relative rates for a set of substrates with systematically growing aromatic side chains using accurate competitive linear regression anal. Increasing the side chain size from Ph to pyrenyl results in a rate acceleration of more than 40 for the major enantiomer. Based on this observation a new catalyst with increased steric bulk has been designed that gives enantioselectivity values of up to s=250. Extensive conformational anal. of the relevant transition states indicates that alc. attack to the more crowded side of the acyl-catalyst intermediate is favored due to stabilizing CH-π-stacking interactions. Exptl. and theor. results imply that enantioselectivity enhancements result from accelerating the transformation of the major enantiomer through attractive non-covalent interactions (NCIs) rather than retarding the transformation of the minor isomer through repulsive steric forces.

Angewandte Chemie, International Edition published new progress about Acylation catalysts (stereoselective). 36428-96-3 belongs to class chlorides-buliding-blocks, name is Pyrene-2-carboxylic acid, and the molecular formula is C17H10O2, Application of Pyrene-2-carboxylic acid.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Uhm, Ki-Nam published the artcileEnantioselective resolution of methyl 2-chloromandelate by Candida antarctica lipase A in a solvent-free transesterification reaction, Name: (S)-Methyl 2-(2-chlorophenyl)-2-hydroxyacetate, the main research area is lipase resolution chloromandelate ester.

Enantiomerically pure 2-chloromandelic acid esters are important chiral building blocks for synthesis of a wide range of pharmaceutical products, such as an anti-thrombotic agent, (S)-clopidogrel. An efficient and novel process for resolution of Me 2-chloromandelate was developed by using a lipase-mediated transesterification. Among 11 hydrolytic enzymes examined, Candida antarctica lipase A (CAL-A) showed the highest enantioselectivity and reaction rate toward Me (S)-2-chloromandelate. Me (R)-2-chloromandelate was obtained in enantiomerically pure form (>99% ee) and 41% yield through the lipase-mediated resolution under a solvent-free condition. CAL-A maintained its catalytic activity during 13 cycles of repeated use without significant decrease in enantioselectivity, indicating that the method is economical and easy to scale-up for com. production of Me (R)-2-chloromandelate.

Journal of Molecular Catalysis B: Enzymatic published new progress about Acylation, stereoselective (enzymic). 32345-60-1 belongs to class chlorides-buliding-blocks, name is (S)-Methyl 2-(2-chlorophenyl)-2-hydroxyacetate, and the molecular formula is C9H9ClO3, Name: (S)-Methyl 2-(2-chlorophenyl)-2-hydroxyacetate.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Li, Ya published the artcileRemote γ-C(sp3)-H Alkylation of Aliphatic Carboxamides via an Unexpected Regiodetermining Pd Migration Process: Reaction Development and Mechanistic Study, Category: chlorides-buliding-blocks, the main research area is remote alkylation aliphatic carboxamide strained bicyclic alkene palladium catalyst.

In the presence of accessible β-C-H bonds, γ-C-H activation of saturated aliphatic carboxamides remains unresolved because β-C-H activation is kinetically favored. This is almost a dogma in the development of C-H activation reactions. Here we report a strategy to change this dogma, as we have found that a Pd-catalyzed, ligand-enabled remote γ-alkylation of saturated aliphatic carboxamides can be realized in the presence of more accessible β-C-H bonds by using strained bicyclic alkenes as the coupling partners. D. functional theory calculations and experiments suggested that the realization of the present reaction is due to a change in the regiodetermining step from commonly encountered irreversible C-H activations, which are reversible here, to an unexpected Pd migration process, which is regiodetermining. This is a new strategy to achieve γ-C-H activation, compared with the previous strategy, making γ-C-H activation both the turnover- and regiodetermining step.

ACS Catalysis published new progress about Alkylation catalysts, regioselective. 3032-32-4 belongs to class chlorides-buliding-blocks, name is 2-Amino-3,6-dichlorobenzoic acid, and the molecular formula is C7H5Cl2NO2, Category: chlorides-buliding-blocks.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Ghosh, Arun K. published the artcileAsymmetric total synthesis of the gastroprotective microbial agent AI-77-B, Recommanded Product: Methyl 4,4,4-trichlorobutanoate, the main research area is gastroprotective pseudopeptide microbial agent AI77B asym total synthesis dihydroisocoumarin; coumarin dihydroiso condensation hydroxy amino acid; leucinal stereoselective alkylation alkynyl ester methoxycyclohexadiene regioselective Diels Alder; aldol reaction Curtius rearrangement homologation; AI-77-B; Asymmetric synthesis; Natural products; Total synthesis.

An enantioselective total synthesis of the pseudopeptide microbial agent AI-77-B, which has shown potent antiulcerogenic properties, is described. The synthesis is convergent and involves the assembly of a dihydroisocoumarin fragment and a hydroxy amino acid. The dihydroisocoumarin derivative was synthesized by means of a Diels-Alder reaction between 1-methoxy-1,3-cyclohexadiene and an alkynyl ester derivative as the dienophile. The alkynyl ester was obtained stereo-selectively by two different synthetic routes: (1) A stereoselective alkylation of leucinal, and (2) a titanium enolate-mediated anti-aldol reaction with trichlorobutyraldehyde, a novel homopropargylaldehyde equivalent The stereocenters of the hydroxy amino acid moiety were generated through a titanium enolate-mediated syn-aldol reaction, Curtius rearrangement, and application of Dondoni’s aldehyde homologation. Condensation of the dihydroisocoumarin and hydroxy amino acid moieties and subsequent removal of the protecting groups furnished optically active AI-77-B.

European Journal of Organic Chemistry published new progress about Aldol condensation, stereoselective. 19376-57-9 belongs to class chlorides-buliding-blocks, name is Methyl 4,4,4-trichlorobutanoate, and the molecular formula is C5H7Cl3O2, Recommanded Product: Methyl 4,4,4-trichlorobutanoate.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Bester, Stephanie M. published the artcileStructural and mechanistic bases for a potent HIV-1 capsid inhibitor, Application of 3-Bromo-6-chloro-2-fluorobenzaldehyde, the main research area is GS 6207 preparation antiviral HIV1 capsid inhibitor.

The potent HIV-1 capsid inhibitor GS-6207 is an investigational principal component of long-acting antiretroviral therapy. We found that GS-6207 inhibits HIV-1 by stabilizing and thereby preventing functional disassembly of the capsid shell in infected cells. X-ray crystallog., cryo-electron microscopy, and hydrogen-deuterium exchange experiments revealed that GS-6207 tightly binds two adjoining capsid subunits and promotes distal intra- and inter-hexamer interactions that stabilize the curved capsid lattice. In addition, GS-6207 interferes with capsid binding to the cellular HIV-1 cofactors Nup153 and CPSF6 that mediate viral nuclear import and direct integration into gene-rich regions of chromatin. These findings elucidate structural insights into the multimodal, potent antiviral activity of GS-6207 and provide a means for rationally developing second-generation therapies.

Science (Washington, DC, United States) published new progress about Anti-HIV agents (anti-HIV-1 agents). 886615-30-1 belongs to class chlorides-buliding-blocks, name is 3-Bromo-6-chloro-2-fluorobenzaldehyde, and the molecular formula is C7H3BrClFO, Application of 3-Bromo-6-chloro-2-fluorobenzaldehyde.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Bladen, Chris published the artcileSynthesis and Evaluation of 1,4-Dihydropyridine Derivatives with Calcium Channel Blocking Activity, Application of 2-Chloro-3-(trifluoromethyl)benzaldehyde, the main research area is quinolinone hexahydro carboxylate aryl preparation calcium channel blocker; pyridine dihydro cyclohexanone fused carboxylate preparation calcium channel blocker.

1,4-Dihydropyridines (DHPs) are an important class of L-type calcium channel blockers that are used to treat conditions such as hypertension and angina. Their primary target in the cardiovascular system is the Cav1.2 L-type calcium channel isoform, however, a number of DHPs also block low-voltage-activated T-type calcium channels. Here, the synthesis of a series of novel fused dihydropyridines I (R1 = H, Me; R2 = Me, Et, i-Bu, t-Bu, PhCH2, 3-pyridylmethyl; R3 = 2,3-F2, 2-Cl-3-F3C, 2-HO-5-O2N, 2-PhCO2-5-O2N) and their abilities to block both L- and T-type calcium channels are described. Within this series of compounds, modification of a key ester moiety not only regulates the blocking affinity for both L- and T-type channels, but also allows for the development of DHPs with 30-fold selectivity for T-type channels over the L-type. The data suggest that a condensed dihydropyridine-based scaffold may serve as a pharmacophore for a new class of T-type selective inhibitors.

Pfluegers Archiv published new progress about Hantzsch cyclocondensation reaction. 93118-03-7 belongs to class chlorides-buliding-blocks, name is 2-Chloro-3-(trifluoromethyl)benzaldehyde, and the molecular formula is C8H4ClF3O, Application of 2-Chloro-3-(trifluoromethyl)benzaldehyde.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Yamamoto, Gaku published the artcileRestricted rotation involving the tetrahedral carbon. XLV. Appearance of a maximum in the rotational barriers of 9-(1,1-dimethyl-2-phenylethyl)triptycenes at a medium-sized peri-substituent, Formula: C7H5Cl2NO2, the main research area is kinetics rotational isomerization phenethyltriptycene; equilibrium rotational isomerization phenethyltriptycene; atropisomerism substituent effect phenethyltriptycene; rotational barrier substituent effect phenethyltriptycene; potential barrier substituent effect phenethyltriptycene; proton NMR phenethyltriptycene.

The rotational isomers of seven I (R = H, F, OMe, Cl, Br, CF3, Me; R1 = H, Cl; R2 = H, OMe, Cl, Me) were stereoselectively prepared and their rotational isomerization kinetics were determined; compounds with relatively small R and R2 (F and OMe) had larger barriers than I (R = R2 = H, R2 = Cl) and I (R, R2 = Cl, Br, Me, CF3) had lower barriers even though R and R2 were relatively large. This anomaly is due to large mol. deformations. The equilibrium constants for the atropisomerism and the 1H NMR are discussed.

Bulletin of the Chemical Society of Japan published new progress about Conformational transition enthalpy. 3032-32-4 belongs to class chlorides-buliding-blocks, name is 2-Amino-3,6-dichlorobenzoic acid, and the molecular formula is C7H5Cl2NO2, Formula: C7H5Cl2NO2.

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics