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Dichlorophenylphosine reacts with 2,2'-dilithio-1,1'-binaphthalene to produce 7-phenyldinaphthol(2,1-b:1',2'-d)phosphole, which undergoes a dephenylation alkylation reaction, involving a lithium-stimulated phosphole anion formation, generating unsubstituted- and alkyl-substituted phospholes. X-ray analysis reveals the strain in the phosphole ring and rapid interconversion of atropisomeric conformers is responsible for the fluxional nature of dinaphthophospholes. Variable-temperature NMR studies help determine the energy barrier for the interconversion while P-substituted dinaphthophosphepines do not exhibit atropisomerism.

The synthesis of (6R)-isodolastatin 10 involves the use of a side reaction associated with the synthesis of dolaphenine. X-ray crystallographic studies of (6R)-isodolastatin 10 reveal the absence of intramolecular hydrogen bonding involving carbonyl groups or amide hydrogens. However, intermolecular hydrogen bonding occurs at N7, O16a, N23 and O24a with adjacent molecules. Molecular modeling studies help determine the energy barrier between cis and trans conformers.

1H and P-NMR spectroscopy and X-ray crystallography were used to examine the configurations of heterocyclic six-membered rings possessing O,N,S and P atoms and the different steric and stereoelectronic reactions which function in the conformational equilbria of 1,3,2-oxazaphosphorinanes. The differing conformational characteristics of 1,3,2-dioxa- and 1,3,2-oxazaphosphorinanes which contain three-coordinate phosphorus, were observed.

X-ray crystallography is used in resolving the three dimensional structure of bovine profilin-beta-actin. Several local variations in the structure of beta-actin are present in comparison with alpha-actin. A five degree rotation between some of its primary domains is also noticed. Actin molecules are similar in structure to the oligomeric protein arrangements. The actin crystal has molecules in the form of ribbons, which is caused due to intermolecular contacts two of which have profilin.

A practical and efficient synthesis of spirobarbiturates of type III in presence of NH acidity of the imide function of the hydrophilic linker element is reported. The structural characterization based on both X-ray crystallography and spectroscopic analysis showed type II [beta]-turn formation.

Constrained versions of anabasine, a naturally occurring nAChR ligand was designed and synthesized to generate nicotinic acetylcholine receptor (nAChR) ligands selective for the [alpha]4[beta]2 and [alpha]7 subtype receptors. All compounds synthesized exhibited high affinity of the [alpha]4[beta]2 nAChR subtype, a subset bound with high affinity for the [alpha]7 receptor subtype, selectively over the [alpha]3[beta]4 receptor subtype.

The density functional theory electronic structure calculations are carried out to study the various stereoelectronic effects observed on the molecular geometries and state-energy splittings of ligated monocopper dioxygen complexes.

A set of optimized parameters for continuum solvation calculations of carbohydrates in conjunction with the Carbohydrate Solution Force Field are presented. The results obtained for the solvation free energies for explicit and implicit solvents could be applied to design models of mixed carbohydrate-protein systems.

A family of chiral cyclic oxamides is prepared by the condensation of optically active 1,2-diamines with diethyl oxalate. The crystal packing analysis of many 2,3-piperazinodiones has shown that strong NH...O[double bond]C intermolecular hydrogen-bonding interactions generating the chain motif has resulted in the formation of 3-D networks as well as with the use of the cyclic hydrogen-bond motif tape structures.

An efficient protocol is developed for copper-catalyzed olefin aziridination by using 5-methyl-2-pyridinesulfonamide or 2-pyridinesulfonyl azide as the nitrenoid source. Chelation-assisted strategy is used for producing aziridines with a range of aryl olefins even in the absence of external ligands.

A new family of N-form immonium-type coupling reagents is described that have differed in their carbocation skeleton structure. The fluoroamidinium salt has performed very well in the presence of only 1 equiv of base, thus confirming the effect of the proton acceptor in the reaction.

Three metabolically stable analogues of the hypothetical intermediate obtained after phosphate elimination in the lumazine synthase-catalyzed reaction are synthesized and analyzed as lumazine synthase inhibitors. The crystal structure of Mycobacterium tuberculosis lumazine synthase in complex with one of the inhibitors has provided a model of the conformation of the intermediate occurring immediately after phosphate elimination.

The scope of the reaction of the tetrabromocalixarene derivative with alcohols under solvolytic conditions in trifluoroethanol (TFE) or hexafluoroisopropanol (HFIP) is analyzed. The reaction of de-tert-butylated tetrabromo derivative with m-xylene in HFIP followed by methylation of the crude product has afforded the tetraxylyl derivative.

A series of structurally novel chiral ionic liquids is synthesized, which have either chiral cation, chiral anion or both. Chiral anions have displayed intermolecular chiral recognition and enantiomeric discrimination is found for a chiral ionic liquid composed of a chiral anion and achiral cation toward another chiral molecule such as a quinone derivative.

The isolation and X-ray crystallographic structural characterization of two conformers arising from rotation along a diacetylenic bond is reported. The results demonstrate the [pi]-stacking in novel pyrene derivatives in solution as well as in solid state.

A comprehensive study of the reactivity of the C-B bond in Suzuki-Miyaura palladium-catalyzed cross-couplings with aryl/heteroaryl halides is described. The reaction involves the facile conversion of substituted 3-methoxypyridazines into the corresponding pyridazin-3(2H)-ones with good functional group tolerance.

The intramolecular Rh-catalyzed amination of saturated C-H bonds, stereocontrolled synthesis of di-, tri-, tetra- and pentasubstituted piperidines from simple 2-sulfamoyloxymethyl piperidine derivatives is demonstrated. Direct application to the total synthesis of iminosugars and related compounds demonstrates the systems potential use to generate various bioactive azacycloalkanes by iterative and direct heterocyclic scaffold decoration.

The novel synthesis of 3-substituted-3,4-dihydro-2H-1,3-benzothiazin-2-ones is described. The synthesis has depended on the highly regioselective palladium-catalyzed carbonylation of 2-substituted-2,3-dihydro-1,2-benzisothiazoles to produce the corresponding 3,4-dihydro-2H-1,3-benzothiazin-2-one derivatives.

Ferrocene-linked bis(nucleobase) and chimeric nucleobase conjugates are synthesized from mono- and bis(hydroxybutyl)ferrocene through Mitsunobu reaction. The studies of ferrocene bis(nucleobase) conjugates have shown two-dimensional supramolecular organizations of backbones through self-assembled Watson-Crick and reverse Watson-Crick type pairs.

The thioenols derived from cyanomonothiocarbonylmalonamides and a cyanodithiocarbonylmalonamide are very reactive species and they have reacted under various conditions. Radical mechanisms, nucleophilic substitutions and condensations are some of the mechanisms used for these reactions.

The qualitative relation between the electric characteristics and binding affinity of a complex receptor-ligand is described. The binding interactions of any complex are analyzed by using small computational resources with acceptable reliability of the results.

The X-ray crystallography technique is applied for the imaging of the noncrystalline materials, cells and single protein complexes. The localization of the specific multiprotein complexes inside the cells is studied.

The small differences between the solution and crystal structure of a membrane protein complex, the cytochrome [b.sub.6]f isolated from the thermophilic cyanobacterium Mastigocladus laminosus is described. The results suggest that the short excited state lifetime of Chlorophyll a (cha a) is critical for the function of the [b.sub.6]f complex.

The article explains the application of the Diels-Alder reaction for the efficient synthesis of tetra-ortho-substituted biaryls. The reactions include the interactions between the propargylic tertiary alcohols and cyclic oxygenated dienes and hence are found to be extremely efficient.

The article explains the synthesis of various iptycene-derived pyridazines and phthalazines. These compounds are found to be widely used as transition metals in several conjugated electronics.

A new approach for the total synthesis of nominine is discussed.

The various dimerization and isomerization reactions of the [alpha]-lithiated terminal aziridines are discussed. The aziridines are found to be extremely important for the synthesis of synthetically and biologically important targets.

The article explains the displacement of the [C.sub.10] acetoxy group of benzo[alpha]pyrene-7,8,9,10-tetrahydrotetraol tetraacetates, which is normally mediated by fluorinated alcohol. The approach has been found to be extremely beneficial for the synthesis of diol epoxide-deoxyguanosine adducts.

X-ray crystallography is used for the preparation and characterization of the perchlorate complexes of manganese, nickel and zinc with hexamethylenetetramine (HMTA). The perchlorate ion is attached to metal through water and the complexes have undergone thermal decomposition in two steps.

A short and practical synthesis of methyl 1-hydroxy-6-oxo-2-cyclohexenecarboxylate known as a component of salicortin and tremulacin is reported.

The isolation and structural characterization of anthecularin, a minor lactone with novel ring system from Greek Anthemis auriculata (Asteraceae) is reported. Anthecularin exhibits antitrypanosomal and antiplasmodial activity capable of inhibiting two key enzymes of the plasmodial type II fatty acid biosynthesis pathway.

The synthesis of various unsymmetrical and symmetrical tetraarylethylenes from reaction of diphenylmethyllithium with variety of substituted benzophenones is demonstrated. The reaction could be used to prepare various triphenyl-ethylene (TPE)-based triads.

The three-dimensional distribution function theory of molecular liquids is used to study the binding of noble gases to the hen egg-white lysozyme in the aqueous solution. The analysis can also be easily used for predicting the protein-ligand binding sites and affinities.

The procedure for synthesis of unsymmetrical terphenyls by employing sequential chemoselective Suzuki-Miyaura (SM) reactions is described.

The organic-terbium hybrid compound created with the azido molecule, 2-methoxy benzoic acid tris-(2-methoxybenzoyl)hydrazide, which demonstrates three-photon-excited green emission, is reported.

Empirically derived factors are used to predict the structures of 1,2,3-trifluorobenzene, 1,3,5-trifluorobenzene, 2,6-difluoropyridine, and 2,6-dicholoropyridine. Comparisons are made between experimental and theoretical structures.

The study explains the effects of the addition of the phenoxathiin cation radical ([PO.sup.+]) to different acyclic alkenes and nonconjugated dienes in acetonitrile solution (MeCN). The reaction has been found to be very useful for the synthesis of (E)- and (Z)-(10-phenoxathiiniumyl)alkenes and (E)- and (Z)-(10-phenoxathiiniumyl)dienes on basic alumina.

Various studies are conducted to analyze the effect of different substituents and conformations on the optical rotations of substituted cyclic oxides and other related compounds. The analysis reveals that the anomeric effect highly affects the rotation of these compounds.

The study results of the nonlinear absorptive property of a novel metal cluster [[W[S.sub.4][Cu.sub.3]I[(4-bpy).sub.3].sub.n] show that the cluster has strong nonlinear absorption under the 8 ns pulse excitation and a relatively weak nonlinear absorptive property under the picosecond pulse excitation.

The original synthetic pathway is described for the preparation of new members of the class of thiaCPS-oxides. The proposed strategy allows the obtainment of these cages in mild reaction conditions.

The processivity, substrate binding and mechanism of cellulose hydrolysis are discussed. Processivity was controlled by residues in the catalytic cleft.

The total synthesis of the unnatural enantiomer of merrilactone A is described based on a novel desymmetrization strategy. The natural and unnatural enantiomers of synthetic merrilactone A have equally promoted neurite outgrowth in primary neuronal cultures.

The organocatalytic enantioselective synthesis of vinyl-substituted all-carbon quaternary stereocenters is carried out via nucleophilic vinylic substitution by [alpha]-substituted-[alpha]-cyanoacetates. This reaction is simple to perform and has proceeded with good yield, high enantiomeric excess and excellent control of the double-bond geometry.

4,5-Diiodopentacyclo[4.3.0.[0.sup.2,4].[0.sup.3,8].[0.sup.5,7]]nonane is treated with n-butyllithium and tert-butyllithium to generate a highly pyramidalized alkene, pentacyclo[4.3.0.[0.sup.2,4].[0.sup.3,8].[0.sup.5,7]]non-4-ene. Ab initio calculations have shown pentacyclo[4.3.0.[0.sup.2,4].[0.sup.3,8].[0.sup.5,7]]non-4-ene to be one of the most highly pyramidalized alkenes.

A new approach to the ring EFHG-tetracyclic core fragment of the marine secondary metabolite diazonamide A is described. This methodology could be applied to the tyrosine-indole derivative to give the EFHG-tetracyclic core of diazonamide A.

The development of a concise route for the preparation of (4S-phenylpyrrolidin-2R-yl)methanol and 2S-methyl-4S-phenylpyrrolidine from 4-hydroxyproline is reported. It features a stereoselective intramolecular Heck cyclization and the double reduction of the aromatic cyclic sulfonamide functionality.

A simple and efficient synthesis of hitherto unknown chlolestanofluorene and its derivatives from the readily available cholestanone as the starting material is described. An appropriately substituted fluorene derivative (R = OMe) forms a highly colored (chiral) cation-radical that could be isolated as robust hexachloroantimonate salt.

A simple method was developed for access to molecules that contain both ketone and N-H aziridine functionalities. The compounds have undergone highly selective reduction and carbonyl addition reactions, thus making them versatile precursors to complex amines.

A trisubstituted tetrahydrofuran representing C10-C18 of the marine algal toxin (-)-gymnodimine was prepared via a highly stereoselective iodine-mediated cyclization of an acyclic alkene bearing a bis-2,6-dichlorobenzyl (DCB) ether. The formation of a cis-2,5-disubstituted tetrahydrofuran in the process has conformed to a stereodirecting effect by the DCB group proposed by Bartlett and Rychnovsky.

A concise and efficient protocol was developed for regioselective synthesis of 2,3,4-substituted pyrroles from readily available polarized ketene S,S- and N,S-acetals and activated methylene isocyanides. Some of the pyrroles are useful intermediates for the synthesis of biologically important compounds like distamycin and netropsin.