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The conversion into 6,7‐dihydro‐5H‐dibenz[c,e]azepine (DAZ) N‐protected amides is a viable route for the determination of the absolute configuration of chiral 2‐substituted carboxylic acids. The biphenyl moiety of DAZ, besides being a probe of chirality for the electronic circular dichroism (ECD) spectroscopy, makes these systems suitable for configuration assignment by exploiting the chirality amplification...
In this article, the most advanced extensions of solvation models to chiroptical properties of solvated systems will be reviewed. The main aspects determining the complex phenomenon of solvation will be first discussed in terms of the physical interactions beyond them and successively translated in a computational language introducing the specific models. A particular attention will be devoted to...
Enantiopure Ti(IV) complexes bearing pseudo‐C3 amino triphenolate ligands have been synthesized and characterized. The complexes bearing ortho phenyl groups act as 1H NMR chiral solvating agent (CSA) for the stereochemical analysis of a series of sulfoxides. The coordination of a Lewis base coligand (sulfoxide) and the presence of aromatic rings are the key structural factors for the efficiency of...
Fourier transform infrared vibrational circular dichroism (FTIR‐VCD) measurements have gone through major advances in the last decade. A major thrust in these advances was to find ways that can minimize the VCD spectral artifacts and obtain the VCD signals at enhanced signal quality. However, all these advances are not incorporated in FTIR‐VCD instruments manufactured by some commercial manufacturers...
Six new phosphite ligands were prepared and their efficiency as chiral ligands was investigated in the copper‐catalyzed asymmetric conjugate addition of dimethylzinc to diethyl 3‐phenylpropylidenmalonate (5), affording the addition product with ees up to 74%. Moreover, a simple and straightforward route to floral fragrances Phenoxanol, Citralis, and Nitrile Citralis in optically active form through...
The enantioselective organocatalytic methanolysis of cis‐1,2,3,6‐tetrahydrophthalic anhydride mediated by quinidine derivatives with pyridazine or anthraquinone core was investigated, carrying out a detailed nuclear magnetic resonance study of the conformational preferences of the alkaloid catalysts in the pure solvent and in the presence of the reaction substrates and products. No significant interaction...
When a racemic mixture is fully consumed the products may still be enantiomerically enriched. In particular, the regiodivergent kinetic resolution is a process in which a single chiral catalyst or reagent reacts with a racemic substrate to form regioisomers possessing an opposite configuration on the newly‐formed stereogenic centers. This review reports the major advances in the field of the copper‐catalyzed...
Toxins produced by phytopathogenic fungi assume great importance because of their involvement in several plant diseases. Although such pathogens are known to have seriously damaged crops, forest, and environmental resources, they represent a very important tool to develop new environmentally friendly herbicides and fungicides. This review deals with the relationships between the biological activity...
Lipocrine has been selected as an effective candidate for in vivo investigation because of its multiple biological properties, namely inhibition of AChE and BChE activities, inhibition of AChE‐induced Aβ aggregation, and ability to protect cells against reactive oxygen species. To evaluate the possibility for lipocrine to become a lead and to be developed as a multipotent drug for the treatment of...
In this work, we present the characterization of an enantiomeric pair of fluorescent dye organogelators and the properties of their stable gel at low concentration in organic solvents. The gels of both enantiomers and of their mixtures were analyzed by differential scanning calorimetry, circular dichroism (CD), atomic force microscopy, UV–vis absorption, and fluorescence. The acquired data were supported...
Indolizidine alkaloids have attracted considerable attention because of their vast array of structural diversity and varied biological activity. This article relates the results that we obtained in the field of the total synthesis of indolizidines from α‐amino acids, based on the rhodium‐catalyzed hydroformylation of N‐allylpyrroles intermediates. The formed pyrrolylbutanals undergo an intramolecular...
A convenient method for the stereoselective synthesis of diasteroisomeric vinyl epoxides (−)‐2α and (−)‐2β, the carba analogs of D‐galactal and D‐allal‐derived vinyl epoxides 1αand 1β, has been elaborated starting from tri‐O‐acetyl‐D‐glucal. The key step of this synthesis is an application of the known Claisen thermal rearrangement of a glucal derivative, the vinyl allyl ether (+)‐3b, which allows...
The transfer of chirality from a guest molecule to an achiral host is the subject of significant interest especially when, upon chiral induction, the chiroptical response of the host/guest complex can effectively report the absolute configuration (AC) of the guest. For more than a decade, dimeric metalloporphyrin hosts (tweezers) have been successfully applied as chirality probes for determination...
The IR and Near infrared (NIR) vibrational circular dichroism (VCD) spectra of molecules endowed with noncentral chirality have been investigated. Data for fundamental, first, and second overtone regions of (S)‐2,3‐pentadiene, exhibiting axial chirality, and methyl‐d3 (R)‐ and (S)‐[2.2]paracyclophane‐4‐carboxylate, exhibiting planar chirality have been measured and analyzed. The analysis of NIR and...
In this review, we present a comprehensive overview of the molecular studies on human tropoelastin domains accomplished by Tamburro and co‐workers in the last decade. The used approach is the reductionist approach applied to human tropoelastin and is based on the observation that the tropoelastin gene exhibits a cassette‐like organization, with a regular alternation of cross‐linking and hydrophobic...
We describe herein the investigation of the stereodynamic processes occurring in a series of 1‐aryl‐2,2‐dimethylindanols, by dynamic NMR. When the aryl moiety is a mesityl or a 2‐methyl‐1‐naphthyl, the rotational barrier exceeds the 25 kcal/mol, so that stable atropisomers are observed. In two cases, all the chiral‐atropisomeric species have been separated by enantioselective HPLC, and the comparison...
Critical main‐chain length for peptide helix formation in the crystal (solid) state and in organic solvents has been already reported. In this short communication, we describe our results aiming at assessing the aforementioned parameter in water solution. To this goal, we synthesized step‐by‐step by solution procedures a complete series of N‐terminally acetylated, C‐terminally methoxylated oligopeptides,...
The measurement of optical rotation (OR) and optical rotatory dispersion has been finding renewed interest for some years, because of advancement in computational methods and in the performance of new experiments. Here, we shortly review the traditional and most‐used experimental methods. We define and discuss the two main types of approaches in measuring OR: the intensity method and the optical null...
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