Antibiotic resistance represents a worldwide concern, especially regarding the outbreak of methicillin-resistant Staphylococcus aureus, common cause for serious skin and soft tissues infections. A major contributor to aureus antibiotic is NorA efflux pump, which able extrude selected antibacterial drugs biocides from membrane, lowering their effective concentrations. Thus, inhibition promising challenging strategy that would allow recycling substrate antimicrobial agents. Among inhibitors,...

Influenza virus infections represent a serious concern to public health, being characterized by high morbidity and significant mortality. To date, compounds targeting the viral ion-channel M2 or neuraminidase are drugs available for treatment of influenza, but emergence drug-resistant mutants renders search novel targets their possible inhibitors major priority. Recently, we demonstrated that RNA-dependent RNA polymerase (RdRP) complex can be an optimal target protein–protein disruption...

The free energies of activation for the aryl-aryl rotation 17 biphenyl derivatives, bearing a heavy heteroatom (S, Se, Te, P, Si, Sn) as ortho substituent, have been measured by variable temperature NMR. These numbers, so called B values, represent meaningful measure steric hindrance exerted selected substituents. DFT computations match quite satisfactorily experimental barriers and ground state geometries well (determined, in two cases, X-ray diffraction). present values extend available...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic and steric effects in the addition of electrophilic 1,3-dicarbonylalkyl radicals to styrenesEnrico Baciocchi Renzo RuzziconiCite this: J. Org. Chem. 1991, 56, 15, 4772–4778Publication Date (Print):July 1, 1991Publication History Published online1 May 2002Published inissue 1 July 1991https://pubs.acs.org/doi/10.1021/jo00015a037https://doi.org/10.1021/jo00015a037research-articleACS PublicationsRequest reuse permissionsArticle...

Abstract 3-Acyl- and 3-carboalkoxyfurans can be prepared in 30–55% yield by the oxidative addition of 1,3-dicarbonyl compounds to vinylic acetates induced eerie ammonium nitrate.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT1,2- And 1,4-addition in the reactions of carbonyl compounds with 1,3-butadiene induced by cerium(IV) ammonium nitrateEnrico Baciocchi and Renzo RuzziconiCite this: J. Org. Chem. 1986, 51, 10, 1645–1649Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1 1986https://pubs.acs.org/doi/10.1021/jo00360a002https://doi.org/10.1021/jo00360a002research-articleACS PublicationsRequest reuse permissionsArticle...

Someone who says "A" should be prepared to also say "B": In contrast cyclohexane model-based A values, biphenyl model-derived B values are powerful tools quantify steric repulsion in and conformational behavior of ortho-substituted aromatic compounds.Torsional barriers 15 biphenyls have been determined computationally using the B3LYP density functional experimentally by variable-temperature ("dynamic") nuclear magnetic resonance. Taking advantage 3'-isopropyldimethylsilyl group as a novel...

Five diastereomers of ruthenium(II) complexes based on quinolinophaneoxazoline ligands were investigated by vibrational circular dichroism (VCD) in the mid-IR and CH stretching regions. Diastereomers differ three sources chirality: planar chirality quinolinophane moiety, central an asymmetric carbon atom oxazoline ring, ruthenium atom. VCD, allied to DFT calculations, has been found be effective disentangling various forms chirality. In particular, a VCD band is identified region directly...

(R)-4-Hydroxy-, -4-fluoro-, -4-bromo-, and -4-iodo[2.2]paracyclophanes have been prepared their absolute configuration assigned on the basis of chemical correlations. Different relationships between specific optical rotation group polarizability found depending ability substituents to conjugate with aromatic ring. At least for 4,7-disubstituted [2.2]paracyclophanes, effects seem be additive, independent wavelength used. An equation has derived which allows predict, a satisfactory...

The size of a series typical substituents has been probed by dynamic NMR measurements the barriers to aryl-aryl rotation corresponding biphenyls. resulting B values are meaningful because only mono-ortho substituted compounds were investigated and thus results not compromised non-additivity multiple steric effects. On basis chosen model system ethynyl cyano groups found be slightly smaller than phenyl ring. In contrast, vinyl and, in particular, formyl proved larger phenyl. latter difference...

At the beginning of this article an in-depth comparison electrophilic and nucleophilic aromatic heterocyclic substitution processes examines their scopes applicability in a new light. In subsequent parts, recent progress area halide hydride displacement from pyridines is highlighted. Particular attention paid to leaving group aptitudes fluoride chloride, effect ‘passive’ substituents on reaction rates, control relative reactivity at halogen-bearing 4- versus 2-(or 6-)positions.

The role played by the C*-H based modes (C* being chiral carbon atom) and large amplitude motions in vibrational absorption (VA) circular dichroism (VCD) spectra is investigated. example of an adduct dimethyl fumarate anthracene, i.e., dimethyl-(+)-(11R,12R)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylate, two deuterated isotopomers thereof specially synthesized for this goal, are considered. By comparing experimental DFT calculated undeuterated species, we demonstrate that bending,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRelative rates for the addition reactions of malonyl radical to substituted styrenes induced by cerium(IV) ammonium nitrate and tributyltin hydride. A comparisonEnrico Baciocchi, Bernd Giese, Hassan Farshchi, Renzo RuzziconiCite this: J. Org. Chem. 1990, 55, 22, 5688–5691Publication Date (Print):October 1, 1990Publication History Published online1 May 2002Published inissue 1 October...

By making use of a novel diastereotopicity probe, namely C(CF(3))(2)OH, it has been possible to measure by very low temperature (19)F NMR spectroscopy the elusive aryl-aryl rotation barriers biphenyls bearing an OH or F group in one ortho position. The experimental values (5.4 and 4.4 kcal mol(-1), respectively) are matched those from ab initio calculations (5.3 4.3 respectively).

Abstract With the aim of finding and characterizing new simple organic molecules (SOM) generating circularly polarized luminescence (CPL), we test here nine [2]paracyclo[2](5,8)‐quinoliphane derivatives, whose circular dichroism (CD) spectra were previously measured at short wavelengths in a study encompassing also OR VCD (CD IR). Completion CD is carried out with attention paid to weaker longer wavelength features. The observed signs CPL are compared band longest found coincident except two...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegio- and Stereoselective Synthesis of Unsaturated Carbonyl Compounds Based on Ceric Ammonium Nitrate-Promoted Oxidative Addition Trimethylsilyl Enol Ethers to Conjugated DienesAnna Belli Paolobelli, Paolo Ceccherelli, Ferdinando Pizzo, Renzo RuzziconiCite this: J. Org. Chem. 1995, 60, 15, 4954–4958Publication Date (Print):July 1, 1995Publication History Published online1 May 2002Published inissue 1 July...

The vibrational absorption spectra and circular dichroism (VCD) of both enantiomers 4-X-[2.2]paracyclophanes (X = COOCD3, Cl, I) have been recorded for a few regions in the range 900−12000 cm-1. analysis VCD two IR regions, 900−1600 cm-1 2800−3200 cm-1, is conducted by comparing with DFT calculations corresponding spectra; latter region reveals common motifs modes three molecules aliphatic CH stretching fundamentals, whereas mid-IR region, one able to identify specific signatures arising...