Synthesis of 5-(Aryl)amino-1,2,3-triazole-containing 2,1,3-Benzothiadiazoles via Azide-Nitrile Cycloaddition Followed by Buchwald-Hartwig Reaction.

An efficient access to the novel 5-(aryl)amino-1,2,3-triazole-containing 2,1,3-benzothiadiazole derivatives has been developed. The method is based on 1,3-dipolar azide-nitrile cycloaddition followed by Buchwald-Hartwig cross-coupling to afford the corresponding -aryl and ,-diaryl substituted 5-amino-1,2,3-triazolyl 2,1,3-benzothiadiazoles under NHC-Pd catalysis. The one-pot diarylative Pd-catalyzed heterocyclization opens the straightforward route to triazole-linked carbazole-benzothiadiazole D-A systems.

Synthesis of CF-Containing Spiro-[Indene-Proline] Derivatives via Rh(III)-Catalyzed C-H Activation/Annulation.

An efficient method of accessing new CF-containing spiro-[indene-proline] derivatives has been developed based on a Cp*Rh(III)-catalyzed tandem C-H activation/[3+2]-annulation reaction of 5-aryl-2-(trifluoromethyl)-3,4-dihydro-2-pyrrole-2-carboxylates with alkynes. An important feature of this spiro annulation process is the feasibility of dehydroproline moiety to act as a directing group in the selective activation of the aromatic C-H bond.

Algorithm of Estimation of the Degree of Porosity Homogeneity of Foamed Concretes by Local Volumes by X-ray Computed Tomography Method.

X-ray CT is widely used to study the structure of foam concrete, the quality of which depends on the uniformity in porosity in local volumes (LV) of the samples. The purpose of this work is to substantiate the need to assess the degree of homogeneity of samples in terms of porosity according to LV. To achieve the goal, an appropriate algorithm has been developed and programmed in MathCad.

Synthesis of Functionalized Isoquinolone Derivatives via Rh(III)-Catalyzed [4+2]-Annulation of Benzamides with Internal Acetylene-Containing α-CF-α-Amino Carboxylates.

A convenient pathway to a new series of α-CF-substituted α-amino acid derivatives bearing pharmacophore isoquinolone core in their backbone has been developed. The method is based on [4+2]-annulation of (pivaloyloxy) aryl amides with orthogonally protected internal acetylene-containing α-amino carboxylates under Rh(III)-catalysis. The target annulation products can be easily transformed into valuable isoquinoline derivatives via a successive aromatization/cross-coupling operation.

Diastereoselective Synthesis of Highly Functionalized Proline Derivatives.

An efficient way to access highly functionalized proline derivatives was developed based on a Cu(I)-catalyzed reaction between CF-substituted allenynes and tosylazide, which involved a cascade of [3 + 2]-cycloaddition/ketenimine and a rearrangement/Alder-ene cyclization to afford the new proline framework with a high diastereoselectivity.

Synthesis of Functionalized Azepines via Cu(I)-Catalyzed Tandem Amination/Cyclization Reaction of Fluorinated Allenynes.

An efficient method for the selective preparation of trifluoromethyl-substituted azepin-2-carboxylates and their phosphorous analogues has been developed via Cu(I)-catalyzed tandem amination/cyclization reaction of functionalized allenynes with primary and secondary amines.

General Method of Synthesis of 5-(Het)arylamino-1,2,3-triazoles via Buchwald-Hartwig Reaction of 5-Amino- or 5-Halo-1,2,3-triazoles.

An efficient access to the novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed. The method is based on Buchwald-Hartwig cross-coupling reaction of 5-Amino or 5-Halo-1,2,3-triazoles with (het)aryl halides and amines, respectively. As result, it was found that palladium complex [(THP-Dipp)Pd(cinn)Cl] bearing expanded-ring -heterocyclic carbene ligand is the most active catalyst for the process to afford the target molecules in high yields.

New Unsymmetrically Substituted Benzothiadiazole-Based Luminophores: Synthesis, Optical, Electrochemical Studies, Charge Transport, and Electroluminescent Characteristics.

Three new benzothiadiazole (BTD)-containing luminophores with different configurations of aryl linkers have been prepared via Pd-catalyzed cross-coupling Suzuki and Buchwald-Hartwig reactions. Photophysical and electroluminescent properties of the compounds were investigated to estimate their potential for optoelectronic applications. All synthesized structures have sufficiently high quantum yields in film.

Lossen rearrangement by Rh(III)-catalyzed C-H activation/annulation of aryl hydroxamates with alkynes: access to quinolone-containing amino acid derivatives.

A convenient and robust method for the preparation of new CF-containing 2-quinolones has been developed a Rh(III)-catalyzed C-H activation/Lossen rearrangement/annulation cascade of -pivaloyloxy-arylamides with internal alkynes bearing an α-CF-α-amino acid moiety on the triple bond. This work expands the scope of valuable products that are available through C-H activation/annulation reactions of arylamides in organic synthesis.

Synthesis of α-CF-substituted E-dehydroornithine derivatives via copper(i)-catalyzed hydroamination of allenes.

An efficient synthetic approach to novel α-CF3-substituted E-dehydroornithine derivatives and their phosphorus analogues has been developed via the Cu(i)-catalyzed hydroamination of trifluoromethyl-containing α-allenyl-α-aminocarboxylates and α-allenyl-α-aminophosphonates with primary and secondary amines.

Dataset of working fluid parameters and performance characteristics for the oxy-fuel, supercritical CO cycle.

This article provides the dataset of working fluid parameters and performance characteristics for the oxy-fuel, supercritical CO cycle by the thermodynamic optimization procedure employed in the research article "Thermodynamic optimization and equipment development for a high efficient fossil fuel power plant with zero emissions" (Rogalev et al., 2019) [1]. The performance characteristics of the different air separation units, which were used for the investigation of an influence of the produced oxygen purity on power consumption, are presented.

Rhodium(iii)-catalyzed CF-carbenoid C-H functionalization of 6-arylpurines.

An efficient method for the CF3-carbenoid C-H functionalization of 6-arylpurines has been developed. This protocol uses readily available methyl 3,3,3-trifluoro-2-diazopropionate as a cross-coupling partner and proceeds smoothly under chelation-controlled Rh(iii) catalysis. The reactions provide the corresponding carbene insertion products with high regioselectivity within a few hours and allow the introduction of both the CF3 and carboxylate functions into biologically important purine molecules including nucleoside derivatives.

Fluorinated Unsymmetrical N,N'-Diaryl Imidazolium Salts-New Functionalized NHC-Ligand Precursors.

An efficient and scaled-up synthesis of the imidazol-2-ylidene-based unsymmetrical NHC precursors bearing the sterically demanding hexafluoroisopropylalkoxy group [(CF ) (OR)C-] at the ortho position of the N-aryl substituent was developed. The key step of the method involved the transformation of a Mes-substituted oxazolinium tetrafluoroborate salt through the reaction with the corresponding binucleophilic fluoroalkyl-substituted aniline. The subsequent post-modification of the resulting hydroxyl-containing salt through a simple one-step O-alkylation protocol provided access to a new family of unsymmetrical fluorinated NHC precursors.

Stereoselective Alkane Oxidation with meta-Chloroperoxybenzoic Acid (MCPBA) Catalyzed by Organometallic Cobalt Complexes.

Cobalt pi-complexes, previously described in the literature and specially synthesized and characterized in this work, were used as catalysts in homogeneous oxidation of organic compounds with peroxides. These complexes contain pi-butadienyl and pi-cyclopentadienyl ligands: [(tetramethylcyclobutadiene)(benzene)cobalt] hexafluorophosphate, [(C₄Me₄)Co(C₆H₆)]PF₆ (); diiodo(carbonyl)(pentamethylcyclopentadienyl)cobalt, Cp*Co(CO)I₂ (); diiodo(carbonyl)(cyclopentadienyl)cobalt, CpCo(CO)I₂ (); (tetramethylcyclobutadiene)(dicarbonyl)(iodo)cobalt, (C₄Me₄)Co(CO)₂I (); [(tetramethylcyclobutadiene)(acetonitrile)(2,2'-bipyridyl)cobalt] hexafluorophosphate, [(C₄Me₄)Co(bipy)(MeCN)]PF₆ (); bis[dicarbonyl(B-cyclohexylborole)]cobalt, [(C₄H₄BCy)Co(CO)₂]₂ (); [(pentamethylcyclopentadienyl)(iodo)(1,10-phenanthroline)cobalt] hexafluorophosphate, [Cp*Co(phen)I]PF₆ (); diiodo(cyclopentadienyl)cobalt, [CpCoI₂]₂ (); [(cyclopentadienyl)(iodo)(2,2'-bipyridyl)cobalt] hexafluorophosphate, [CpCo(bipy)I]PF₆ (); and [(pentamethylcyclopentadienyl)(iodo)(2,2'-bipyridyl)cobalt] hexafluorophosphate, [Cp*Co(bipy)I]PF₆ (). Complexes and catalyze very efficient and stereoselective oxygenation of tertiary C-H bonds in isomeric dimethylcyclohexanes with MCBA: cyclohexanols are produced in 39 and 53% yields and with the / ratio (of isomers with mutual - or -configuration of two methyl groups) 0.

Impacts of brown carbon from biomass burning on surface UV and ozone photochemistry in the Amazon Basin.

The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or "brown" carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths.

Generation of monoclonal antibody against trans-resveratrol.

Monoclonal antibody (MAb) against trans-resveratrol (t-RSV) was obtained from hybridoma clones constructed from splenocytes of BALB/c mice immunized with carrier proteins (bovine serum albumin [BSA] and ovalbumin [OVA]) coupled with synthetic hapten mimicking t-RSV structure. The t-RSV-BSA derivate was more efficient at induction of the immune response than t-RSV-OVA. However, the use of t-RSV-OVA was advantageous during selection of hybridoma clones constructed from splenocytes of t-RSV-BSA-immunized mice.

Cyclobutene ring-opening of bicyclo[4.2.0]octa-1,6-dienes: access to CF3-substituted 5,6,7,8-tetrahydro-1,7-naphthyridines.

An efficient method for the synthesis of novel CF(3)-substituted tetrahydro-1,7-naphthyridines including cyclic α-amino acid derivatives has been developed. The method is based on unusual cyclobutene ring-opening of bicyclo[4.2.

Click-chemistry approach to isoxazole-containing α-CF3-substituted α-aminocarboxylates and α-aminophosphonates.

A convenient strategy for the synthesis of isoxazole-containing α-CF(3)-substituted α-aminocarboxylates and α-aminophosphonates have been developed. The method is based on copper-catalyzed 1,3-dipolar cycloaddition of different aromatic nitrile oxides to functionalized acetylenes.

Ruthenium-catalysed synthesis of fluorinated bicyclic amino esters through tandem carbene addition/cyclopropanation of enynes.

The reaction of fluorinated 1,6- and 1,7-enynes, containing the moiety N(PG)C(CF(3))(CO(2)R), with diazo compounds in the presence of [RuCl(cod)(Cp*)] (cod=cycloocta-1,5-diene, Cp*=C(5)Me(5) , PG=protecting group) as the catalyst precursor leads to the formation of fluorinated 3-azabicyclo[3.1.0]hexane-2-carboxylates and 4-azabicyclo-[4.

Synthesis of functionalized bisphosphonates via click chemistry.

An efficient general synthetic approach giving the possibility for facile, rapid and cheap access to a wide range of novel nitrogen-bisphosphonates (N-BPs) as potent drug candidates, based on the reaction of mono- and bis-propargyl-substituted bisphosphonates with a variety of azides under Cu(i) catalysis ("click" methodology), has been developed. The method allows the incorporation of two functionalities into the N-BP molecule simultaneously, as well as to ligate in situ two N-BPs to one another via the one-pot reaction of organic dibromides with propargyl-substituted bisphosphonates, generating both the diazide and Cu(I) moieties.

Methyltrifluoropyruvate imines possessing N-oxalyl and N-phosphonoformyl groups--precursors to a variety of alpha-CF3-alpha-amino acid derivatives.

Convenient routes to methyl 2-oxalylimino- and 2-(phosphonoformimido)-3,3,3-trifluoropropanoates have been elaborated, based on the reaction of methyl trifluoropyruvate with ethyl oxamate or diethyl carbamoylphosphonate, respectively, followed by dehydration. The compounds obtained are useful synthetic intermediates toward a variety of novel 3,3,3-trifluoroalanine derivatives that are potential drug candidates.

A New Strategy for the Synthesis of alpha-Difluoromethyl-Substituted alpha-Hydroxy and alpha-Amino Acids.

A new method for the preparation of alpha-chlorodifluoromethyl-, alpha-bromodifluoromethyl-, and alpha-difluoromethyl-substituted alpha-hydroxy and alpha-amino acid esters 11, 19-21 is described. The key step of the synthesis is the regioselective alkylation of ketones 5, 7-9 and imines 16-18 with C-nucleophiles. The ketones 7-9 are readily available from 3,3,3-trifluorolactate 1 by a five-step procedure.