Abstract The [3+2] cycloaddition of CF 3 CHN 2 , generated in situ, with electron‐deficient alkenes/alkynes affords ‐substituted pyrazolines/pyrazoles quantitative yields. one‐pot three‐component reaction between CH NH · HCl, NaNO and the substrate proceeds at room temperature dichloromethane/water.

As good as a Pro: Another CF3-substituted amino acid, CF3MePro (see structure), has been added to the arsenal of 19F NMR labels; it is particularly suited for study proline-rich peptides. This acid was carefully designed and chosen from other synthesized isomers, according strict selection criteria, most stable, nonracemizable, conformationally restricted, compatible with solid-phase peptide-synthesis protocols. Supporting information this article available on WWW under...

Multicomponent reactions (MCRs) and microwave-assisted organic synthesis (MAOS) have been used as key methods for the of fused dihydropyrimidine derivatives. The three-component condensation 3-amino-5-alkylthio-1,2,4-triazoles with aromatic aldehydes acetoacetamides under microwave irradiation was developed a rapid efficient solution-phase method high-yielding preparation 7-aryl-2-alkylthio-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamide libraries. In addition, selective reduction...

The supramolecular architecture of crystals five fused hydrocarbons has been analyzed using an approach based on consideration the energy intermolecular interactions. This method allows unambiguous recognition strongly bonded fragments which may be considered as basic structural motif (BSM) crystal packing. Replacement molecules by energy-vector diagrams (hedgehogs) their interactions represents a very efficient tool for graphical representation structure from viewpoint topology...

Analysis of the strengths and directionality intermolecular interactions in crystals containing only one type supramolecular synthon allows suggestion a general classification molecular depending on their basic structural motifs. All may be divided four classes namely (I) with isotropic packing building units; (II) columnar where motif (BSM) is chain/column; (III) layered layers as BSM; (IV) columnar-layered chains/columns primary secondary BSM. Taking into account participation different...

Treatment of TiCl 4 with Bu t NH 2 (6 equivalents) followed by addition bpy (2 equivalents, 4-tert-butylpyridine) or pyridine (py) afforded the five- six-co-ordinate tert-butylimido complexes [Ti(NBu )Cl (bpy) ] n (n = 3*) respectively in good yields. Reaction 3 RNH gave corresponding arylimido derivatives [Ti(NR)Cl (R Ph,* C 6 H Me-4,* NO -4,* Me -2,6 Pr i -2,6). Addition tmen pmdien to respectively) bi- tri-dentate amine complexes, (tmen)] (pmdien)]* (tmen NCH CH NMe , N,N,N′,N ″,N″...

An unprecedented hexanuclear heterotrimetallic Fe/Cu/Co complex bearing two Cu(mu-O)2Co(mu-O)2Fe cores is easily prepared by self-assembly and acts as a remarkable catalyst for the peroxidative oxidation of cycloalkanes under mild conditions.

The potential energy surface for the benzene dimer in stacked conformations (84 points calculated) was computed at MP2(FC)∕6-31+G(2d,2p) level of theory. Electron density (ED) distribution using MP2(FC), B3LYP, and Hartree–Fock methods with same basis set is studied frame topological analysis. It found that ED topology does not depend on method calculation. values its Laplacian cage critical point calculated different are determined to be linearly dependent slope depending set. Correlation...

The trityl alcohols bearing three bromine or iodine atoms at the para-positions of aromatic units, have been known for more than a hundred years. In our case these compounds synthesized in one-pot sequence starting from 1,4-dihalogenobenzenes via mono-lithiation and successive reaction with diethylcarbonate. crystallized different solvent mixtures leading to one structure bromo- (A) structures iodo (B–D). inclusion dichloromethane (C) benzene (D) crystalline lattices has observed. all cases...

An efficient synthesis of 5a-hydroxy-4,5,5a,6,7,8-hexahydropyrazolo[4,3-c]quinolizin-9-ones based on the three-component condensation 5-aminopyrazoles, aromatic aldehydes, and cyclic 1,3-diketones is described. The multicomponent reaction performed under strongly basic conditions applying controlled microwave heating in a sealed vessel involves an unusual base-mediated ring-opening/recyclization 1,3-diketone moiety.

In the present work, conventional static ab initio picture of a water-assisted mechanism tautomerization Nucleic Acid Bases (NABs) in an aqueous environment is enhanced by classical and Car–Parrinello molecular dynamics simulations. The inclusion dynamical contribution vital because formation longevity NAB–water bridge complexes represent decisive factors for further tautomerization. results both dynamic techniques indicate that longest time when such exist significantly shorter than...

Supramolecular synthons in crystals are structural units formed with intermolecular interactions. The assembly of an organic crystal is not just a geometrical interlinking but often the consequence compromise or mutual interference between adjacent synthons. Accordingly, synthon can be major problem systematic engineering especially if it results lack correspondence molecular and structures. Conversely, robustness capacity to withstand essential attribute structure design. These ideas...

The degree of aromaticity six-membered monoheterocycles with IV-VI group heteroatoms (C(6)H(5)X, where X = SiH, GeH, N, P, As, O(+), S(+), Se(+)) was analyzed using the results ab initio calculations at MP2/cc-pvtz level. Values common indices including those based on electronic delocalization properties, structural-dynamic features and magnetic properties all indicate high considered heterocycles. A decrease in is observed increasing atomic number heteroatom, except case pyrylium cation....

A novel kinetic approach based on ab initio calculated rate constants has been developed and implemented in the kTSim program. The proposed allows prediction of distribution reactant product concentrations over time, exclusively computationally obtained constants. newly methodology was used to simulate process evaporation tautomerization guanine cytosine under thermal (T = 490 K, cytosine; T 620 guanine) laser 1000 24 ns pulse) desorption conditions. Both monomolecular bimolecular mechanisms...

Straightforward practical synthetic approaches to 3,4-bis- and 3,4,5-tris(trifluoromethyl)pyrazoles have been developed. The key step of the both syntheses is a transformation carboxylic group in pyrazole core into trifluoromethyl by sulfur tetrafluoride. elaborated protocols allow gram-scale preparation target products. obtained compounds are comprehensively characterized means crystallographic analysis, determination pK(a) values fluorescence measurements.

Cyclobutane diamines (i.e., cis- and trans-1,3-diaminocyclobutane, 6-amino-3-azaspiro[3.3]heptane, 3,6-diaminospiro[3.3]heptane) are considered as promising sterically constrained diamine building blocks for drug discovery. An approach to the syntheses of their Boc-monoprotected derivatives has been developed aimed at preparation multigram amounts compounds. These novel synthetic schemes exploit classical malonate alkylation chemistry construction cyclobutane rings. The conformational...

Alternative reaction pathways for Biginelli-like cyclocondensation reactions using 3-amino-1,2,4-triazole as a 1,3-binucleophile under different conditions lead to several types of products. The literary data is generalized and discussed. Additional results going beyond the generalization are also revealed.

Abstract The reaction of Salen‐like Zn II and Ni precursors with carbacylamidophosphate lanthanide moieties yields six new types 3d–4f compounds. complexes were characterized by means 1 H, 31 P NMR IR spectroscopy, elemental analysis, ESI mass spectrometry, X‐ray diffraction analysis. Depending on the Schiff base ligands, ion adopts either a square‐planar or an octahedral geometry, whereas has tetragonal‐pyramidal geometry. coordination number lanthanides is nine ten. Hydrolytic activities...