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The design and synthesis of a fluorescent light-driven motorized nanocar with a linear geometry is described. Due to its structural design, the nanocar is present as a mixture of two photo-interconvertible diastereomers. An extensive and detailed NMR study allowed the full assignment of the chemical shifts of the two diastereomers in the mixture. The nanocar is expected to translate in a linear motion due to the light-driven motor providing a paddle-wheel like propulsion. The quantum yield of 0.56 and the photostability of the dye make this nanocar suitable for future single-molecule fluorescence microscopy studies. [ABSTRACT FROM AUTHOR]

The isothiourea-catalysed chemo- and enantioselective [2,3]-sigmatropic rearrangement of N , N -diallyl allylic ammonium ylides is explored as a key part of a route to free functionalised α-amino esters and piperidines. The [2,3]-sigmatropic rearrangement proceeds with excellent diastereo- and enantiocontrol (>95:5 dr, up to 97% ee), with the resultant N , N -diallyl α-amino esters undergoing either mono - or bis - N -allyl deprotection. Bis - N -allyl deprotection leads to free α-amino esters, while the mono-deprotection strategy has been utilized in the synthesis of a target functionalised piperidine. [ABSTRACT FROM AUTHOR]

An efficient approach for the enantioselective synthesis of the 1,4-benzodioxane F17807 drug is reported. The developed route relied on two key steps, namely S N Ar and Mitsunobu reactions, which permitted a straightforward access to the title compound with full preservation of the enantiomeric excess throughout the synthetic sequence. [ABSTRACT FROM AUTHOR]

Abstract: 2- and 3-Trifluoromethylmorpholines were prepared in racemic and optically active forms. The synthesis commenced from the commercially available 2-trifluoromethyloxirane. The elaborated procedures were scalable, and the products were obtained in multigram quantities. The obtained compounds were comprehensively characterized by crystallographic analysis, fluorescence measurements, solubility, pK a, logD parameters, and clearance rate. The potential of the synthesized amines as the building blocks for drug discovery is thus demonstrated. [Copyright &y& Elsevier]

Abstract: Optically active (S)-2-aryl-4 (or 5)-phenyl-1,3-oxazolines and (S)-2-fluoroalkyl-4-phenyl-1,3-oxazolines were synthesized from a tandem one-pot reaction of (S)-2-amino-2-phenylethanol with a corresponding carboxylic acid in toluene at 90 °C in the presence of PPh3/CBr4 and excess Et3N. The use of aromatic carboxylic acids were determined to proceed through N-(2-bromo-1-phenyl-ethyl)-arylamides 5 and N-aroyl aziridine intermediates 6, which resulted in the formation of (S)-2-aryl-4-phenyl-1,3-oxazolines and (S)-2-aryl-5-phenyl-1,3-oxazolines, respectively. Concurrently, the reaction with fluorinated aliphatic carboxylic acid substrates proceeded via N-(2-hydroxy-1-phenyl-ethyl)-fluoroalkyl amide intermediates 8, which were converted into N-(2-bromo-1-phenyl-ethyl)-fluoroalkyl amide intermediates 9, and then into (S)-2-fluoroalkyl-4-phenyl-1,3-oxazolines as final products. Reaction mechanisms that mainly passed through the formation of aziridine intermediates 6 in the reaction with aromatic carboxylic acids and the formation of fluoroalkyl amide intermediates 8 and 9 in the reaction with fluorinated aliphatic carboxylic acid were proposed. The acidities of the carboxylic acids that were employed were found to play a key role in the selective formation of various intermediates during this reaction. [Copyright &y& Elsevier]

Abstract: Upper rim-functionalized, di-ionizable calix[4]arene-crown-6 ligands are synthesized and compared with structural isomers having the two acidic side arms attached to the lower rim. Solvent extractions of selected divalent metal cations (alkaline earth metal cations, Pb2+, and Hg2+) from aqueous solutions into chloroform by the upper and lower rim-functionalized, di-ionizable calix[4]arene-crown-6 isomers are utilized to assess the effects of this structural modification on metal ion complexation abilities of the ligands. The observed effects are compared with those reported for analogous di-ionizable calix[4]arene-crown-5 structural isomers. [Copyright &y& Elsevier]

Abstract: A reaction of (S)-2-benzyl-2-(α-methylbenzyl)amino-1,3-propanediol (S)-4a and 2-chloroethyl chloroformate, and the subsequent addition of DBU gave (4R,αS)-4-benzyl-4-hydroxymethyl-3-(α-methylbenzyl)-2-oxazolidinone (4R)-5a (92% de) via a diastereoselective asymmetric desymmetrization process. Debenzylation of (4R)-5a using trifluoromethanesulfonic acid and anisole in MeNO2 gave (R)-4-benzyl-4-hydroxymethyl-2-oxazolidinone (R)-15a, which was converted into (R)-(α-hydroxymethyl)phenylalanine (7) in two steps. N-Boc-α-methylphenylalanine (8), cericlami0ne (9) and BIRT-377 (10) were also synthesized using these asymmetric desymmetrization and debenzylation. [Copyright &y& Elsevier]

Abstract: Muscenone® is a valuable perfume ingredient consisting of a mixture of the E- and Z-isomers of 1 in racemic form as the major constituents. Among them, it is the (R,Z)-isomer, which exhibits the most favorable musk character and by far the lowest threshold; for these superior olfactory properties, pure (R,Z)-1 has recently been commercialized too. We present an efficient route to this precious compound based on an iron-catalyzed cross coupling reaction, a molybdenum-catalyzed alkyne metathesis for the formation of the macrocyclic ring, and a nickel-catalyzed semi-hydrogenation. [Copyright &y& Elsevier]

Abstract: Lipase from Burkholderia cepacia (PSL-C) effectively catalyzed the kinetic resolution of both racemic trans-N,N-diallylcyclohex-4-ene-1,2-diamine (±)-6 and its precursor trans-6-(diallylamino)cyclohex-3-enol (±)-5. The resulting optically active vicinal diamine and β-amino alcohol were converted into a precursor of oseltamivir and a cis-cyclohex-4-ene-1,2-diamine derivative, respectively. [Copyright &y& Elsevier]

Abstract: Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also. [Copyright &y& Elsevier]

Abstract: The synthesis of optically active medium-sized α-aminolactams via ring-closing metathesis is described. The amidation of optically active N-Boc-allylglycine derivatives with N-protected alkenylamine, and ring-closing metathesis resulted in the formation of medium-sized α-aminolactams with good yield. [Copyright &y& Elsevier]

Abstract: The synthesis and phase transitional behaviour of three pairs of enantiomeric supramolecular hexacatenar liquid crystals (LCs) derived from natural α-amino acids such as l/d-alanine, l/d-leucine and l/d-valine are described. Their preparation with high enantiomeric purity was accomplished by condensing optically active (amino acid residue containing) trialkoxy amines with a 3,4,5-trialkoxy cinnamic acid core using a peptide coupling reagent namely, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl-uronium hexafluorophosphate (HBTU). The mesomorphic behaviour of these self-complementing mesogens was ascertained by polarising optical microscopy, differential scanning calorimetry and X-ray diffraction. The compounds exhibit columnar (Col) phase over a wide thermal range. Particularly, a pair of enantiomers derived from l/d-leucine residues notably stabilize hexagonal Col (Colh) phase over a wide temperature range of −5°C to 180°C. Circular dichroism (CD) and FTIR studies suggest the chiral (helical) organization of mesogens within the columns through intermolecular hydrogen bonding; thus, these enantiomers represent one of the rarely reported examples of LCs exhibiting supramolecular Colh phase at room temperature. The gelation studies reveal the ability of these bisamides to form stable supramolecular gels in ethanol caused through H-bonding interactions. [Copyright &y& Elsevier]

Abstract: Two regioisomers of 2-arylpyrazolo[3,4-c]quinolin-4(5H)-ones and 2-arylpyrazolo[4,3-c]quinolin-4(5H)-ones were synthesized by utilizing 3-arylsydnones, ethyl 3-bromopropynoate, and 2-aminophenylboronic acid pinacol ester in presence of catalytic agent Pd(PPh3)4. This efficient one-pot synthesis methodology involved 1,3-dipolar cycloaddition, Suzuki coupling reaction, and intramolecular cyclization three sequence steps. [Copyright &y& Elsevier]

Abstract: Novel naphthyl-modified calix[4]arene was synthesized by click chemistry, and exhibited high affinity and selectivity for p-nitroaniline by the fluorescence spectroscopy. However, the sensitivity toward other anilines 3a–e are negligible. The 1H NMR, 1H NOESY, MALDI-TOF mass spectroscopy and computational calculations revealed the formation of host–guest complex driven by H-bonding and hydrophobic interactions. [Copyright &y& Elsevier]

Abstract: The reactivity of allenyl carboxylates, Ar(R1)CCCH(O2CR2) and their isomeric equivalents the terminal propargylic carboxylates, ArC(R1)(O2CR2)CCH, in gold-catalyzed carbocyclization to indenes provides information on 1,3 and 1,2-carboxylate shifts associated with their interconversion. Allenyl carboxylates transform specifically to 1H-inden-1-yl carboxylates in high yields, under AuI-catalysis. Their equivalent propargylic carboxylates give complex mixtures of indene isomers and elimination products. Mechanistic tests indicate that interconversion of the terminal propargylic carbonate to its allene is at best slow in this case. [Copyright &y& Elsevier]

Abstract: All the eight stereoisomers of 3-acetoxy-11,19-octacosadien-1-ol (1), the male sex pheromone (CH503) of Drosophila melanogaster, were synthesized from two acetylenic starting materials and the enantiomers of 3,4-epoxy-1-butanol PMB ether. Complete separation of the eight isomers of 1 by reversed phase HPLC at −20 °C was achieved after their esterification with (1R,2R)-2-(2,3-anthracenedicarboximido)cyclohexanecarboxylic acid (27), and the natural CH503 was found to be (3R,11Z,19Z)-1. [Copyright &y& Elsevier]

Abstract: A Cu(I)-catalyzed asymmetric cyclopropanation of alkenes with an iodonium ylide has been developed. The copper source, hypervalent iodine source, solvent, and additives all have a significant effect on the yields and enantioselectivities. High enantioselectivity (up to 99:1 er) and diastereoselectivity (95:5 dr trans/cis) were achieved for a wide range of alkenes. Conditions were developed to convert the trans products to the cis isomers. In addition, 1-nitrocyclopropyl carboxylates were transformed into the corresponding substituted cyclopropane amino acids and aminocyclopropanes. Moreover, a comparative study between Zn- and In-mediated reduction reactions of the nitro group in these compounds with regards to the er erosion in the process is also documented. [Copyright &y& Elsevier]

Abstract: To realize the effects of the pyridyl group on the stability, multiplicity, and geometry of isomeric pyridylcarbenes and their heavier Si and Ge analogues, a theoretical study was performed at B3LYP/6-311++G(d,p)//B3LYP/6-31G(d). The behavior of nitrogen atom was totally different in each multiplicity (singlet and triplet), structural isomer (ortho-, meta-, and para-), and divalent center (C, Si, and Ge). All pyridylcarbenes have triplet ground states, while the stable silylene and germylene analogues are singlet. The pyridyl group stabilizes both singlet and triplet states divalent centers with more pronounced effects on the singlet states in the order: carbene>germylene>silylene. While all planar species benefit from common π–p conjugative interaction of the pyridyl ring, in the ortho-isomers of 2-pyridylsilylene and 2-pyridylgermylene there is another interaction, n–p, that leads to two stable non-planar conformers. This finding is confirmed by NBO charges, calculated UV–vis spectra, philicity indices (N and ω), and isodesmic reactions. [Copyright &y& Elsevier]

Abstract: A Rh-catalyzed diastereoselective reductive cyclization, mediated by hydrogen, of optically active 1,6-enynes using chiral BINAP was successfully applied to the total synthesis of four stereoisomers of the proposed structure of lucentamycin A. In order to synthesize two of these four stereoisomers, we successfully constructed chiral proline derivatives bearing cis-carbon substituents at C2 and C3 positions based on Krische’s methodology, which has very rarely been reported. Anti-proliferative activities on HCT-116 cell line and NMR data of these four stereoisomers were compared with those of naturally occurring lucentamycine A. The results show that the proposed structure of lucentamycin A needs revision. [Copyright &y& Elsevier]

Abstract: d-Homotryptophan and its sulfur analogue have been synthesized by Sonogashira coupling between 3-iodoheteroarenes and ethynyloxazolidine followed by reduction of triple bond and oxidation of alcohol to acid. l-Homotryptophan and its oxygen analogue have been synthesized from silylated internal alkyne using Larock’s heteroannulation as the key reaction. The alkynyloxazolidines were synthesized from l-serine and l-glutamic acid, respectively. [Copyright &y& Elsevier]

Abstract: The solid state structure of a lithium mixed anion aggregate, 1, containing aldolate, enolized aldolate, and unenolized ketone, which are all derived from pinacolone, is described. Theoretical calculations (semiempirical PM3 and ab initio HF/6-31G*) are used to quantify the relative stabilities of a model aldolate and also enolized aldolate isomers. Ab initio calculations indicate isomers with a cubane core, for both aldolates and enolized aldolate anions, are stabilized over open ring or ladder derivatives. The highly unsymmetrical structure of 1 incorporates three distinct components, i.e., two bridging monomeric enolized aldolates, an open monomeric enolized aldolate, and a monomeric aldolate. The composition of 1 is consistent with origination from an aldolate tetramer. [Copyright &y& Elsevier]

Abstract: Our efforts in constructing the ABD-ring of phomactin A through an intramolecular oxa-[3+3] annulation strategy is described. This struggle entailed finding a practical and efficient preparation of annulation precursor, and a realization of the unexpected competing regioisomeric pathway. The success entailed accessing the A-ring through Diels–Alder cycloaddition of Rawal’s diene. Furthermore, the discovery that the regioisomers from the annulation existed as atropisomers with respect to the D-ring olefin and that they could be equilibrated to the desired ABD-tricycle, allowing large quantities of tricycle to be accessed. [Copyright &y& Elsevier]

Abstract: (E)-Trifluoromethyl imines were considered as ideal substrates to be transformed into the corresponding diaziridines by a direct amination reaction with nosyloxycarbamates. The diastereoselective induction was strongly controlled by the N-substituent. Similar results were obtained in the epoxidation reactions performed on the same substrates using m-CPBA as oxidant. Starting from enantiopure imines chiral diaziridines or oxaziridines were obtained with very high enantiopurity. [Copyright &y& Elsevier]

Abstract: E-β-Chloro-α-iodo-α,β-unsaturated esters were converted to single isomer trisubstituted olefins bearing alkyl substituents by using and alkyl-Suzuki cross coupling. The process was highly selective, and the products in all cases were isolated as single isomers. Mechanistic investigations indicated that this process transfers a hydrogen from water to the α-position of the substrate, and then an alkyl group is introduced to the β-position of the intermediate template while replacing a chloride. [ABSTRACT FROM AUTHOR]

Abstract: Pyrazino[1,2-b]isoquinoline-1,4-diones (3) having a bulky activating group at the N(2)-position were rearranged to tetramic acids with a benzo[f]indolizine skeleton (8) in the presence of K t BuO or LHMDS as bases. This rearrangement was diasteroselective for the 6,11a-trans-isomers of the starting compounds. 1-Hydroxy-pyrazino[1,2-b]isoquinolin-4-one (7) afforded a 1-trichloroacetamido derivative (14) after treatment with trichloroacetonitrile and a catalytic amount of sodium hydride as a base, through two subsequent base-promoted transannular rearrangements. In summary, the combination of functions in the piperazine ring of the starting tricyclic compounds conferred to them new reactivities that imply different base-promoted transannular rearrangements and led to unexpected transformations. [ABSTRACT FROM AUTHOR]

Abstract: Palladium-catalyzed hydrostannation reactions of ortho-disubstituted arylalkynes were achieved with total stereo- and regio-selectivity in THF at room temperature. The regioselectivity was found to be under the control of the ortho-substituents (ortho-directing effects, ODE) and pure α-vinylstannanes are produced in good yields and as single isomers regardless of the substituents’ nature. These hydrostannation α-products are precursors of choice for the preparation of stereo-defined triarylolefins. [ABSTRACT FROM AUTHOR]

Abstract: Enantioselective alkynylation of aldehydes and ketones was accomplished using trimethoxysilylalkynes as alkynylating reagents and lithium 3,3′-diphenylbinaphtholate as a catalyst. Optically active propargylic alcohols were obtained in good to high chemical yields and enantioselectivities. Alkynylation of acetylpyridines afforded biologically active pyridyl propargylic alcohols in good enantioselectivities. [Copyright &y& Elsevier]

Abstract: Stereoselective inverse conjugate addition of carbonucleophiles to allenoates bearing a chiral auxiliary in the ester moiety afforded optically active α,β-unsaturated carboxylic esters bearing a new stereocenter at the δ position. The rationalization of the observed selectivity was supported by semi-empirical molecular orbital calculations. [Copyright &y& Elsevier]

Abstract: Triphenylphosphine catalyzes the regio- and stereospecific addition of ketoximes to acylacetylenes, whereas classical conditions using acetylene (KOH/DMSO, 70°C) are unsuitable for this purpose. The reaction proceeds under mild conditions (CH2Cl2, rt, 7h) to afford (E)-(O)-2-(acyl)vinylketoximes (92–98% stereoselectivity) in a yield of up to 85%. The (E)-adducts obtained are energetically less favorable than the corresponding (Z)-isomers and are gradually enriched with (Z)-isomers, thus indicating the kinetic control of (E)-stereoselectivity of the reaction. [ABSTRACT FROM AUTHOR]

Abstract: The enantiomers of (11Z,19Z)-3-acetoxy-11,19-octacosadien-1-ol were synthesized from the enantiomers of 3,4-epoxy-1-butanol PMB ether. Its racemate was also synthesized. Its (S)-isomer and racemate were shown to possess the same pheromone activity as CH503, a long-lived inhibitor of male courtship in Drosophila melanogaster, although the racemate was less active. [ABSTRACT FROM AUTHOR]

Abstract: Steric and electronic parameters, such as the anomeric effect (AE) and gauche effect play significant roles in steering the North⇆South equilibrium of nucleosides in solution. Two isomeric oxa-bicyclo[3.1.0]hexane nucleosides that are conformationally locked in either the North or the South conformation of the pseudorotational cycle were designed to study the consequences of having the AE operational or not, independent of other parameters. The rigidity of the system allowed the orientation of the orbitals involved to be set in ‘fixed’ relationships, either antiperiplanar where the AE is permanently ‘on’, or gauche where the AE is impaired. The consequences of these two alternatives were subjected to high-level calculations and measured experimentally by X-ray crystallography, hydrolytic stability of the glycosyl bond, and pK a values. [ABSTRACT FROM AUTHOR]

Abstract: A new general approach for the synthesis of optically active α-amino acids has been developed. The key steps involve a ruthenium catalysed cross-coupling reaction to give a range of α,β-unsaturated ketones, which were then reduced to allylic secondary alcohols in the presence of a chiral CBS oxazaborolidine. A thermal Overman rearrangement was used to prepare a series of allylic trichloroacetimidates and these were converted under standard conditions to the target α-amino acids in good overall yields. [Copyright &y& Elsevier]

Abstract: ‘Deficiency catalysis’ is the concept applied to metalation chemistry that increments of TMEDA or an equivalent or two of an ether activate alkyllithiums in hydrocarbon media. Amplification of this concept to conflicting reports of α- and ortho-metalation of ortho-methylanisole (o-MA) is explored. Both regioselective metalations were realized in selectivity ratios of >7:1 for the desired isomers. Some rationale is provided for the various selectivities. These results are at variance with prior results and interpretations thereof found in the literature. [Copyright &y& Elsevier]

Abstract: Toward the goal of gaining further insight into carbocation–π interactions, bridged-ring aromatic alkene model systems are being investigated in which one isomer will permit π complexation of an intramolecular tertiary carbocation with a benzene ring, but the other isomer will not. The syntheses of three sets of such isomers, having, respectively, benzobicyclo[3.2.1]octene, benzobicyclo[2.2.1]heptene, and benzobicyclo[4.2.1]nonene structures, are described. [Copyright &y& Elsevier]

Abstract: An efficient method for one-pot synthesis of isomeric ellipticine derivatives through CuI/La(OTf)3 catalyzed sequential inter/intramolecular cyclization of substituted alkynes with imines followed by aromatization is reported in good to excellent yields. [Copyright &y& Elsevier]

Abstract: Shape-persistent, optically-active arylamide macrocycles have been designed and approached by using a stepwise, convergent methodology. The source of chirality, an axially-chiral Binol scaffold, incorporates methoxy functionalities in the 2,2′ positions, and carboxylic functionalities in the external 3,3′ positions. The latter can be efficiently elaborated through aromatic amidation to introduce aromatic spacers of differing shapes. The peculiar arrangement of functionalities on the Binol skeleton functions as an element of rigidification of the covalent structure through the formation of stable intramolecular hydrogen bonds. When this element is counterbalanced by the use of a flexible 3,3′-diaminobiphenyl as a spacer, yields for the macrocyclization step increase to values higher than 50%. The recognition properties of this particular macrocycle have been exploited and, while they indicate modest binding affinities towards carboxylate anions, the additional stabilization of neighbouring amide functionalities suitably placed within the covalent framework induces detectable binding of proper difunctional carboxylates. [Copyright &y& Elsevier]

Abstract: Arylaminotetrazole derivatives are synthesized efficiently by the reaction of arylcyanamides and sodium azide in the presence of ZnCl2 under aqueous conditions at reflux. Generally, isomer of 5-arylamino-1H-tetrazole can be obtained from arylcyanamides carrying electron-withdrawing substituent on aryl ring and as the electropositivity of substituent is increased, the product is shifted toward the isomer of 1-aryl-5-amino-1H-tetrazole. [Copyright &y& Elsevier]

Abstract: A convenient one-pot two-step procedure for the synthesis of hydroxyiminodihydrobenzofurans assisted by microwave irradiation in presence of silica gel is described herein. Cyclic 1,3-dicarbonyl compounds reacted smoothly with various nitroolefins to furnish hydroxyiminodihydrobenzofuran derivatives as the mixture of E and Z isomers. Clean reaction conditions, no work-up procedure, easy isolation and good yields of the products are the salient features of the methodology. [Copyright &y& Elsevier]

Abstract: Tertiary aliphatic β- and γ-nitro nitriles and ketones deuterated in (several) selected positions had been synthesized. The deuterated nitro compounds served as a starting material for the corresponding deuterium labeled nitrones or hydroxylamines (reducing with aluminum amalgam). Further oxidation of the last two groups of compounds with sodium periodate or m-CPBA afforded the relevant deuterated tertiary C-nitroso compounds. [Copyright &y& Elsevier]

Abstract: Substituted five-membered cyclic nitrones (pyrroline N-oxides) have been obtained in good to high yields from tertiary γ-nitro ketones and nitriles employing aluminium amalgam as a reducing agent in moist diethyl ether or THF. Attempts to obtain cyclic amino nitrones from α- or β-nitro nitriles failed and only the corresponding hydroxylamines have been isolated. Both nitrones and hydroxylamines have been used for synthesis of tertiary C-nitroso nitriles or ketones. [Copyright &y& Elsevier]

Abstract: The synthesis of two selectively deuterium-labelled 4-(((S)-1-((S)-1-((S)-2-methylbutoxy)-1-oxopropan-2-yloxy)-1-oxopropan-2-yloxy)carbonyl)phenyl 4′-(heptyloxy)biphenyl-4-carboxylate derivatives is reported. A new preparation strategy was developed in order to optimise the yields as well as the optical purity, this property being of fundamental importance for the optical applications of this ferroelectric liquid crystal. [Copyright &y& Elsevier]

Abstract: In the course of a research program focused on the preparation of libraries of new chemical entities derived from 3-alkoxypyrazoles, we studied their N-pyridylation using 2, 3 or 4-bromopyridines. This was achieved using Cristau and Taillefer copper-catalyzed arylation method and mostly led to the 3-alkoxy-1H-pyrazol-1-yl pyridine isomer along with lesser amount of the alternative 5-alkoxy-1H-pyrazol-1-yl pyridine. The structures of these isomers were often established via their chemical transformations and sometimes recourse to unambiguous synthetic routes for comparison purposes. The alternative use of 2-fluoropyridine-based arylation was also investigated and lifted some of the limitations encountered in the course of this study. [Copyright &y& Elsevier]

Abstract: The separation of cis and trans isomers is relevant for biological and nutritional applications, silver-exchanged zeolite Y was prepared and applied for the treatment of mixtures of cis and trans geometrical isomers of mono- and polyunsaturated fatty acid methyl esters (FAMEs). cis FAMEs were adsorbed into zeolite with a high degree of selectivity (cis/trans ratio in the range of 1.9–3.2). The effectiveness was due to the synergism of the π-complexation between the silver ion and the double bonds and the different FAME structures trapped into the zeolite cages. Some indication of the complex stabilities came from theoretical studies using unsaturated lipids. A prototype cartridge was also designed for application in the fractionation of cis/trans FAME mixtures. [Copyright &y& Elsevier]

Abstract: The hypervalent iodine reagents o-iodoxybenzoic acid (IBX) and bis(trifluoro-acetoxy)iodobenzene (BTI) are shown to be general reagents for regio-controlled oxidation of polycyclic aromatic phenols (PAPs) to specific isomers (ortho, para, or remote) of polycyclic aromatic quinones (PAQs). The oxidations of a series of PAPs with IBX take place under mild conditions to furnish the corresponding ortho-PAQs. In contrast, oxidations of the same series of PAPs with BTI exhibit variable regiospecificity, affording para-PAQs where structurally feasible and ortho-PAQs or remote PAQ isomers in other cases. The structures of the specific PAQ isomers formed are predictable on the basis of the inherent regioselectivities of the hypervalent iodine reagents in combination with the structural requirements of the phenol precursors. IBX and BTI are recommended as the preferred reagents for regio-controlled oxidation of PAPs to PAQs. [Copyright &y& Elsevier]

Abstract: The cyanoamidation of olefins was achieved. When N-(2-vinylphenyl)cyanoformamides were treated with palladium catalyst, intramolecular cyanoamidation took place to give corresponding 3,3-disubstituted oxindoles. P(t-Bu)3 showed a remarkable effect on this reaction. When it was used with Pd(dba)2, the reaction was completed in 15min at 100°C for many substrates. Furthermore, the enantioselective cyanoamidation was accomplished with Pd(dba)2 and an optically active phosphoramidite to provide optically active 3,3-disubstituted oxindoles. Manipulation of the resulting oxindoles has been studied. [Copyright &y& Elsevier]

Abstract: The syntheses of structural isomers of bis-indole alkaloid caulerpin are investigated. Construction of the caulerpin skeleton is based on the Fisher indolization reaction of the appropriate cyclooctane-diones or cyclooctanone. In addition, a step-by-step synthesis of one isomer from possible four cyclic indole-tetramers has first been described. [Copyright &y& Elsevier]

Abstract: The reaction of α-chloroformylarylhydrazines hydrochloride with quinoline under air provided the corresponding 2-aryl-2H-[1,2,4]triazoloquinolin-3-ones 3a–3d in 33–42% yields and unexpected isomeric 2-aryl-2H-[1,2,4]triazoloisoquinolin-3-ones 4a–4d in 30–42% yields. These two isomers were isolated and fully characterized by spectroscopic methods including X-ray crystallography. By employing 3-methylquinoline as the starting material under the same condition, the reaction only gave compound 3e–3h as sole products in 70–82% yields without the formation of isomers. A plausible mechanism was proposed through electrophilic aromatic reaction, the tandem ring cyclization and ring-opening, and oxidation for the generation of 2-aryl-2H-[1,2,4]triazoloisoquinolin-3-ones (4). [Copyright &y& Elsevier]

Abstract: SmI2-induced reaction of (E)-β-alkoxyvinyl (R)- and (S)-sulfoxides with aldehydes effected a highly stereoselective intramolecular cyclization to give 2,6-anti-2,3-cis- and 2,6-syn-2,3-trans-tetrahydropyran-3-ols, respectively. The reaction of (Z)-(R)-isomer gave 2,6-syn-2,3-cis-tetrahydropyran-3-ol and a ring-opened product, and that of (Z)-(S)-isomer yielded many products. [Copyright &y& Elsevier]

Abstract: An efficient method for preparation of arylaminotetrazoles is reported using natrolite zeolite as a natural catalyst. Generally, isomer of 5-arylamino-1H-tetrazole can be obtained from arylcyanamides carrying electron-withdrawing substituent on aryl ring and as the electropositivity of substituent is increased, the product is shifted toward the isomer of 1-aryl-5-amino-1H-tetrazole. This method has the advantages of high yields, simple methodology, short reaction times and easy work-up. The catalyst can be recovered by simple filtration and reused in good yields. [Copyright &y& Elsevier]