Copper-mediated three-component synthesis of 3-cyanoimidazo[1,2-a]pyridines

2015 ◽  
Vol 51 (84) ◽  
pp. 15378-15381 ◽  
Author(s):  
Qiaodong Wen ◽  
Ping Lu ◽  
Yanguang Wang
Keyword(s):  
Cascade Reaction ◽  
Benzyl Cyanide ◽  
Reaction Proceeds ◽  
Component Approach

A copper-mediated three-component approach towards the synthesis of 3-cyanoimidazo[1,2-a]pyridines from 2-aminopyridines, acetophenones and benzyl cyanide was developed. This cascade reaction proceeds through a copper-mediated oxidative release of cyanide from benzyl cyanide, a copper-mediated Ortoleva–King reaction, and a copper-catalyzed cyanation.

A metal-free radical cascade reaction of phosphine oxides with 2-aryloxy phenylacetylenes to assemble diphosphonyl xanthene derivatives

2021 ◽  
Author(s):  
Tao Fan ◽  
Yan Liu ◽  
Caina Jiang ◽  
Yanli Xu ◽  
Yan-Yan Chen
Keyword(s):  
Free Radical ◽  
Transition Metal ◽  
Cascade Reaction ◽  
Phosphine Oxides ◽  
Metal Free ◽  
Mild Conditions ◽  
Xanthene Derivatives ◽  
Reaction Proceeds ◽  
Radical Cascade

A radical cascade reaction of 2-aryloxy phenylacetylene with phosphine oxides promoted by K2S2O8 was developed, provided diphosphonyl xanthenes as products. This reaction proceeds under transition metal-free and mild conditions with...

Catalyst-Free Synthesis of Chromane-Type N,O-Acetals via Intramolecular Addition of Phenols to Enamines

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3604-3621 ◽  
Author(s):  
Vitaly A. Osyanin ◽  
Dmitry V. Osipov ◽  
Irina V. Melnikova ◽  
Kirill S. Korzhenko ◽  
Irina A. Semenova ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Secondary Amines ◽  
Catalyst Free ◽  
Reaction Proceeds ◽  
New Strategy

A new strategy to 2-aminochromanes through catalyst-free cascade reaction of 3-trifluoroacetyl-4H-chromenes and 4H-chromene-3-carbaldehydes with cyclic secondary amines is presented. The reaction proceeds through subsequent 1,4- and 1,2-additions of amine, bimolecular elimination of trifluoroacetamide or formamide, and 6-exo-trig cyclization. The latter stage is a very rare example of addition of phenols to enamines. The obtained semicyclic N,O-acetals were applied as useful precursors for the synthesis of other chromanes.

Copper(II)-Promoted Oxidation/[3+2]Cycloaddition/Aromatization Cascade: Efficient Synthesis of Tetrasubstituted NH-Pyrrole from Chalcones and Iminodiacetates

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Oxidative Cyclization ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.

Synthesis of γ,δ-Unsaturated Esters and Amides via Au(I)-Catalyzed Reactions of Aryl Ynol Ethers or Ynamides with Allylic Alcohols

Synthesis ◽  
2021 ◽  
Author(s):  
Souta Misawa ◽  
Asaki Miyairi ◽  
Yoshihiro Oonishi ◽  
Steven P. Nolan ◽  
Yoshihiro Sato
Keyword(s):  
Claisen Rearrangement ◽  
Cascade Reactions ◽  
Cascade Reaction ◽  
Allylic Alcohols ◽  
Unsaturated Esters ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Ynol Ethers ◽  
Catalyzed Reactions ◽  
Reaction Attack

Polarized alkynes such as ynol ethers and ynamides have attracted much attention due to their inherent unique reactivity. Herein, we report Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reactions of aryl ynol ethers and ynamides with allylic alcohols. At the first stage (hydroalkoxylation) of this cascade reaction, attack of allylic alcohols to aryl ynol ethers or ynamides occurs at the α-position of the polarized alkynes in an entirely regioselective manner. Claisen rearrangement of the resulting adducts subsequentially takes place to give γ,δ-unsaturated esters or amides, respectively. The [Au(IPr)NTf2] catalyst is most effective for this reaction, and the reaction proceeds under mild conditions (in the case of aryl ynol ether: in THF, 60 °C; in the case of ynamides: in toluene, 80 °C) in an atom-economical way.

scholarly journals Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers

2019 ◽  
Vol 15 ◽  
pp. 1822-1828
Author(s):  
Shuhei Sumino ◽  
Takahide Fukuyama ◽  
Mika Sasano ◽  
Ilhyong Ryu ◽  
Antoine Jacquet ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Coupling Reactions ◽  
Chain Reaction ◽  
One Pot ◽  
Component Process ◽  
Reaction Proceeds ◽  
Radical Cascade

Four-component coupling reactions between xanthogenates, alkenes, CO, and sulfonyl oxime ethers were studied. In the presence of hexabutylditin, working as a propagating radical reagent, the chain reaction proceeds, as expected, taking into account reagents polarities, affording the corresponding functionalized α-keto oximes. Although yields are modest, this rare one-pot four-component process is easy to carry out and the resulting compounds, bearing multiple functionalities, have the potential for further elaboration.

An Expedient, Direct, Three-Component Approach for the Synthesis of 4-Thioarylpyrroles

Synthesis ◽  
2019 ◽  
Vol 51 (21) ◽  
pp. 4023-4033 ◽  
Author(s):  
Venkatachalam Rajeshkumar ◽  
Chinnaraj Neelamegam ◽  
Sambandam Anandan
Keyword(s):  
Sulfur Atom ◽  
Ammonium Formate ◽  
Direct Access ◽  
One Pot ◽  
Simple Protocol ◽  
Reaction Proceeds ◽  
Component Approach ◽  
Synthetic Application

A three-component strategy for the synthesis of 4-thioarylpyrroles from 1,4-enediones, thiols, and ammonium formate in one-pot has been developed. The reaction proceeds through the sequential thiol-Michael/Paal–Knorr reaction of 1,4-enediones with the formation of one new C–S and two C–N bonds. The operationally simple protocol provides direct access to the highly functionalized 4-thioarylpyrroles with free-NH in good to excellent yields. The synthetic application of resulting 4-thioarylpyrroles was demonstrated by oxidation of the sulfur atom to the corresponding sulfoxide and sulfone.

scholarly journals Theoretical investigation of Banert cascade reaction

2018 ◽  
Vol 5 (4) ◽  
pp. 171075 ◽  
Author(s):  
S. Bhattacharyya ◽  
K. Hatua
Keyword(s):  
Activation Energy ◽  
Density Functional Theory ◽  
Density Functional ◽  
Energy Parameter ◽  
Cascade Reaction ◽  
Sigmatropic Rearrangement ◽  
Functional Theory ◽  
Rate Determining Step ◽  
Rate Of Reaction ◽  
Reaction Proceeds

Computational inside of Banert cascade reaction for triazole formation is studied with B3LYP/6-31G(d,p) level of theory. The reaction proceeds mainly by SN2 initial chloride displacement rather than SN2′-type attack. Furthermore, according to the rate of reaction calculation, SN2 displacement is much faster than SN2′ displacement in the order of 8. The [3,3]-sigmatropic rearrangement for the conversion of propargyl azide into triazafulvene has been proved as the rate-determining step having highest activation energy parameter. Solvent effect on total course of reaction has been found negligible. Furthermore, effects of different density functional theory functionals and functional groups on activation energies of [3,3]-sigmatropic rearrangement of propargyl azide were also studied. BHHLYP, ω B97XD, M062X and BMK calculated Δ G ‡ are consistent with B3LYP.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

Solar photocatalysis mediated by ZnO for the removal of last traces of Indigo carmine dye pollutant from water

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Veena Vijayan ◽  
Suguna Yesodharan ◽  
E. P. Yesodharan
Keyword(s):  
Indigo Carmine ◽  
Parent Compound ◽  
Oxygen Demand ◽  
Green Technology ◽  
Solar Photocatalysis ◽  
Reaction Proceeds ◽  
Transient Intermediates ◽  
Significant Chemical ◽  
Hydroxyl Free Radicals ◽  
Purification Of Water

Solar photocatalysis as a potential green technology for the removal of traces of the dye pollutant Indigo carmine (IC) from water is investigated using ZnO as the catalyst. Degradation/decolorization alone does not result in complete decontamination as seen from the significant Chemical Oxygen Demand (COD) of water even after the parent compound has disappeared completely. The degradation proceeds through many intermediates which also get mineralized eventually but slowly. Oxalic acid is identified as a stable slow mineralizing degradation product which itself is formed from other transient intermediates. Effect of various parameters such as catalyst dosage, concentration of the dye, pH, temperature, presence of contaminant salts etc. on the degradation is investigated and quantified. Oxidants such as S2O82- and H2O2 have only moderate influence on the degradation. The degradation follows variable kinetics depending on the concentration of the substrate. The reaction proceeds very slowly in the absence of O2 indicating the importance of reactive oxygen species and hydroxyl free radicals in photocatalysis. H2O2 formed insitu in the system undergoes concurrent decomposition resulting in stabilization in its concentration. The study demonstrates that solar photocatalysis can be used as a viable tool for the purification of water contaminated with traces of IC.

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