Iminium-functionalized 1,2,3-triazoles by [3+2] cycloaddition reactions of internal acetylenic iminium triflates with organoazides

2019 ◽  
Vol 74 (7-8) ◽  
pp. 585-602
Author(s):  
Christian J. Tontsch ◽  
Holger Gerster ◽  
Gerhard Maas
Keyword(s):  
Microwave Irradiation ◽  
Triple Bond ◽  
Thermal Activation ◽  
Cycloaddition Reactions ◽  
Acetylenic Bond ◽  
Sterically Demanding ◽  
Iminium Ions ◽  
Neutral Compounds ◽  
Very High

AbstractPropyne iminium triflates 1–6 react as dipolarophiles in thermal [3 + 2]-cycloadditions with sufficiently electron rich organoazides to form 1,4,5-trisubstituted 1,2,3-triazoles with iminium functionalization. The reactions require rather strong thermal activation, but can be accelerated by microwave irradiation. The regioselectivity of the cycloaddition at the internal acetylenic bond of 3-cyclopropylpropyne and 3-arylpropyne iminium ions (1–3 and 4, respectively) is very high, but is lowered in the presence of sterically demanding substituents at the opposite end of the iminium-substituted C,C triple bond. The iminium-functionalized triazoles can easily be transformed into neutral compounds; herein reported is the formation of triazolyl ketones 10 by hydrolysis and of tertiary triazolyldimethyl amines 12 by LiAlH4 reduction. When the reduction is performed with sodium boranate or sodium cyanoboranate, amine–borane complexes 15 and 16 are obtained.

scholarly journals Towards High Efficacy of Pd-Au/C Catalyst for Tetrachloromethane Hydrodechlorination

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 338-359
Author(s):  
Magdalena Bonarowska ◽  
Zbigniew Kaszkur ◽  
Krzysztof Matus ◽  
Alicja Drelinkiewicz ◽  
Tomasz Szumełda ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Gas Phase ◽  
Thermal Activation ◽  
Supported Catalysts ◽  
Carbon Support ◽  
Thermal Reduction ◽  
Microwave Oven ◽  
Optimal Conditions ◽  
Catalyst Activation ◽  
Critical Part

We present an efficient strategy for synthesising the PdAu catalysts with a homogeneous PdAu alloy phase for environmentally important hydrodechlorination of tetrachloromethane in the gas phase. The synthesis of carbon-supported catalysts involved two major steps: (i) incorporation of palladium and gold nanoparticles into carbon support and (ii) activation of the catalysts. The critical part of this work was to find the optimal conditions for both steps. Thus, the incorporation of the nanoparticles was carried out in two ways, by impregnation and direct redox reaction method using acetone solutions of metal precursor salts. The activation was performed either by a conventional thermal reduction in hydrogen or flash irradiation in a microwave oven. The homogeneity and structure of the PdAu alloy were found to depend on the catalyst activation method critically. In all cases, we observed better homogeneity for catalysts that were subject to microwave irradiation. Moreover, the flash microwave irradiation of prepared catalysts provided catalysts of better stability and selectivity towards the desired products (hydrocarbons) in the hydrodechlorination of tetrachloromethane as compared to the catalyst obtained by conventional thermal activation in hydrogen.

ChemInform Abstract: Synthesis of Pyrazolo[3,4-b]pyridines by Cycloaddition Reactions under Microwave Irradiation.

ChemInform ◽  
2010 ◽  
Vol 31 (27) ◽  
pp. no-no
Author(s):  
Angel Diaz-Ortiz ◽  
Jose Ramon Carrillo ◽  
Fernando P. Cossio ◽  
Maria J. Gomez-Escalonilla ◽  
Antonio de la Hoz ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Cycloaddition Reactions

scholarly journals 3-Phenyl-N,N,N′,N′-tetramethyl-1-ethyne-1-carboximidamidium bromide

2012 ◽  
Vol 68 (6) ◽  
pp. o1812-o1812 ◽  
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner
Keyword(s):  
Double Bond ◽  
Title Compound ◽  
Triple Bond ◽  
Positive Charge ◽  
Bond Distance ◽  
Double Bond Character ◽  
Acetylenic Bond ◽  
Compound C ◽  
Bond Character

The reaction of 3,3,3-tris(dimethylamino)-1-phenylprop-1-yne with bromine in pentane yields the title compound, C13H17N2 +·Br−. The acetylenic bond distance [1.197 (2) Å] is consistent with a C[triple-bond]C triple bond. The amidinium C=N bonds [1.325 (2) and 1.330 (2) Å] have double-bond character and the positive charge is delocalized between the two dimethylamino groups.

Thermal-Activation & Activity Analysis of Neimenggu High Alumina Coal Gangue

2012 ◽  
Vol 198-199 ◽  
pp. 9-13
Author(s):  
Hai Li Cheng ◽  
Fei Hua Yang ◽  
Jie Zhang ◽  
Yi Wang
Keyword(s):  
High Activity ◽  
Thermal Activation ◽  
Activity Analysis ◽  
Coal Gangue ◽  
High Alumina ◽  
Micro Structure ◽  
Cement Mortars ◽  
Activated Coal ◽  
Activated Coal Gangue ◽  
Very High

In this paper, the Neimenggu high alumina coal gangue was calcined at 400°C~1000°C, its micro-structure in different calcining temperature was studied using XRD and IR, and then the preferred activated condition and the PAI were investigated by testing the strength of cement mortars with activated coal gangue. The result shows that: the optimal calcining temperature of the gangue is 800°C, at this temperature the high activated SiO2 and AI2O3 can be decomposed from the gangue. The activity of the original gangue is very high, the PAI of the cement mortars with 800°C activated coal gangue can achieve to 126%, and thus can be used as high activity cement admixture. The PAI of the high alumina gangue is higher than that of coal gangue from other parts of China.

Tetrakis(phenylethynyl)tin(IV)

2007 ◽  
Vol 63 (11) ◽  
pp. m2762-m2762 ◽  
Author(s):  
Mohammed Lahcini ◽  
Minna T. Räisänen ◽  
Pascal M. Castro ◽  
Martti Klinga ◽  
Markku Leskelä
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Title Compound ◽  
Triple Bond ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Tetrahedral Symmetry ◽  
Acetylenic Bond ◽  
Dimensional Network ◽  
Phenyl Proton

The asymmetric unit of the crystal structure of the title compound, [Sn(C8H5)4], consists of one fourth of a discrete tin complex and one half of another which both possess nearly ideal tetrahedral symmetry; the site symmetries of the two Sn atoms are \overline4 and 2. The bond angles at all acetylide C atoms are almost linear. The Sn—C distances [2.076 (6) and 2.065 (6)–2.069 (6) Å in the two complexes) are short when compared to the sum of the covalent radii of C and Sn (2.177 Å), but consistent with another tetrakis(alkynyl)tin complex. The acetylenic bond distances [1.196 (7) and 1.183 (7)–1.207 (7) Å] are consistent with a triple C[triple-bond]C bond. Therefore, despite the short Sn—C distances, the ligands are mainly σ-bonded to the metal. In the solid state, these complexes form a three-dimensional network via agostic C—H interactions as a phenyl proton in the ortho position interacts with the acetylenic carbon in the α position to the tin center.

scholarly journals Some Aspects of the Chemistry of Alkynylsilanes

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2433-2462 ◽  
Author(s):  
Gerald Larson
Keyword(s):  
Triple Bond ◽  
Cross Coupling ◽  
Diels Alder ◽  
Cycloaddition Reactions ◽  
Aromatic Rings ◽  
Silyl Group ◽  
Unique Character ◽  
Sonogashira Reactions

In amongst the considerable chemistry of acetylenes there lies some unique chemistry of alkynylsilanes (silylacetylenes) some of which is reviewed herein. This unique character is exemplified not only in the silyl protection of the terminal C–H of acetylenes, but also in the ability of the silyl group to be converted into other functionalities after reaction of the alkynylsilane and to its ability to dictate and improve the regioselectivity of reactions at the triple bond. This, when combined with the possible subsequent transformations of the silyl group, makes their chemistry highly versatile and useful.1 Introduction2 Safety3 Synthesis4 Protiodesilylation5 Sonogashira Reactions6 Cross-Coupling with the C–Si Bond7 Stille Cross-Coupling8 Reactions at the Terminal Carbon9 Cross-Coupling with Silylethynylmagnesium Bromides10 Reactions of Haloethynylsilanes11 Cycloaddition Reactions11.1 Formation of Aromatic Rings11.2 Diels–Alder Cyclizations11.3 Formation of Heterocycles11.4 Formation of 1,2,3-Triazines11.5 [2+3] Cycloadditions11.6 Other Cycloadditions12 Additions to the C≡C Bond13 Reactions at the C–Si Bond14 Miscellaneous Reactions

scholarly journals A Rapid Microwave Induced Synthesis of Isonicotinamide Derivatives and their Antifungal Activity

2019 ◽  
Vol 92 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Valentina Bušić ◽  
Karolina Vrandečić ◽  
Tamara Siber ◽  
Sunčica Roca ◽  
Dražen Vikić Topić ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Antifungal Activity ◽  
Ir Spectroscopy ◽  
Microwave Irradiation ◽  
Fusarium Culmorum ◽  
Macrophomina Phaseolina ◽  
Two Dimensional ◽  
Weak Activity ◽  
Very High

Ten novel isonicotinamide derivatives were prepared by quaternization reactions of isonicotinamide with methyl iodide and nine differently substituted 2 bromoacetophenones under rapid microwave irradiation of 10 minutes. The microwave preparations were significantly faster and with yields higher up to 8 times, than the preparations by conventional method. The structures of synthesized molecules were determined by one- and two dimensional NMR and IR spectroscopy, mass spectrometry and elemental analysis. Antifungal activity of all compounds was tested in two different concentrations (10 and 100 µg mL–1) against Fusarium oxysporum, Fusarium culmorum, Macrophomina phaseolina and Sclerotinia sclerotiorum in vitro. From the antifungal assay it can be seen that the most prepared compounds have moderate to weak activity against M. phaseolina and F. culmorum. A very high inhibitory rate was observed against S. sclerotiorum, 62–87.5 % in concentration of 10 µg mL–1 and 83.7–93.2 % in concentration of 100 µg mL–1.

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