ChemInform Abstract: Metal-Free Broensted Acid Mediated Synthesis of Fully Substituted Thiophenes via Chemo- and Regioselective Intramolecular Cyclization of α,α′-Bis(β-oxodithioesters) at Room Temperature.

ChemInform ◽  
2016 ◽  
Vol 47 (20) ◽  
Author(s):  
B. Janaki Ramulu ◽  
Suvajit Koley ◽  
Maya Shankar Singh
Keyword(s):  
Intramolecular Cyclization ◽  
Room Temperature ◽  
Metal Free

Metal-free synthesis of 1H-isochromenes via benzyl ether-assisted, electrophilic addition of diaryl acetylenes

2021 ◽  
Author(s):  
Tzu-Hsuan Kuan ◽  
Trimurtulu Kotipalli ◽  
Cheng-Chun Chen ◽  
Duen-Ren Hou
Keyword(s):  
Intramolecular Cyclization ◽  
Room Temperature ◽  
Electrophilic Addition ◽  
Benzyl Ether ◽  
Metal Free ◽  
Benzyl Ethers ◽  
The Stability ◽  
Diaryl Acetylenes

Bromotrimethylsilane (TMSBr) promoted, intramolecular cyclization of (o-arylethynyl)benzyl ethers to form 1H-isochromenes at room temperature is reported. Further studies indicated that the stability of vinyl carbocations is crucial, similar to the...

Metal-free Brønsted acid mediated synthesis of fully substituted thiophenes via chemo- and regioselective intramolecular cyclization of α,α′-bis(β-oxodithioesters) at room temperature

2016 ◽  
Vol 14 (2) ◽  
pp. 434-439 ◽  
Author(s):  
B. Janaki Ramulu ◽  
Suvajit Koley ◽  
Maya Shankar Singh
Keyword(s):  
Intramolecular Cyclization ◽  
Room Temperature ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Metal Free ◽  
Brönsted Acid

Metal-free Brønsted acid mediated synthesis of tetrasubstituted thiophenes via intramolecular cyclization of α,α′-bis(β-oxodithioesters) is devised at room temperature.

Transition-Metal-Free Synthesis of Pyrrolo[1,2-a]pyrazines via Intramolecular Cyclization of N-Propargyl(pyrrolyl)enaminones

Synthesis ◽  
2017 ◽  
Vol 49 (17) ◽  
pp. 4065-4081 ◽  
Author(s):  
Lyubov Sobenina ◽  
Elena Sagitova ◽  
Igor Ushakov ◽  
Boris Trofimov
Keyword(s):  
Transition Metal ◽  
Intramolecular Cyclization ◽  
Room Temperature ◽  
Cross Coupling ◽  
Metal Free ◽  
Key Steps

A concise transition-metal-free strategy for the synthesis of pyrrolo[1,2-a]pyrazines with enone substituents has been developed. It includes the following key steps: (a) cross-coupling of pyrroles with acyl(bromo)acetylenes in solid alumina at room temperature to give 2-(acylethynyl)pyrroles; (b) addition of propargylamine to the above acetylenes to form the corresponding N-propargylenaminones; and (c) chemo- and stereoselective base-catalyzed (Cs2CO3/DMSO) intramolecular cyclization of the synthesized propargylic derivatives to form (acylmeth­ylidene)pyrrolo[1,2-a]pyrazines of Z-configuration.

Metal-free visible-light-induced aerobic oxidation of α-diazoesters leading to α-ketoesters in air

2021 ◽  
Author(s):  
Ruisheng Liu ◽  
Qishun Liu ◽  
Haoran Meng ◽  
Hongyu Ding ◽  
Jindong Hao ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Aerobic Oxidation ◽  
Metal Free

A metal-free and visible-light-induced strategy has been established for the construction of α-ketoesters via aerobic oxidation of α-diazoesters with dioxygen in air at room temperature.

scholarly journals Giant room temperature elastocaloric effect in metal-free thin-film perovskites

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cheng Li ◽  
Yu Hui Huang ◽  
Jian-Jun Wang ◽  
Bo Wang ◽  
Yong Jun Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Room Temperature ◽  
Entropy Change ◽  
Stress Change ◽  
Chemical Doping ◽  
Metal Free ◽  
Organic Ferroelectrics ◽  
Potential Applications ◽  
Unit Stress

AbstractSolid-state refrigeration which is environmentally benign has attracted considerable attention. Mechanocaloric (mC) materials, in which the phase transitions can be induced by mechanical stresses, represent one of the most promising types of solid-state caloric materials. Herein, we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric (eC) strengths for the (111)-oriented metal-free perovskite ferroelectric [MDABCO](NH4)I3 thin-films. The predicted room temperature isothermal eC ΔSeC/Δσ (eC entropy change under unit stress change) and adiabatic eC ΔTeC/Δσ (eC temperature change under unit stress change) for [MDABCO](NH4)I3 are −60.0 J K−1 kg−1 GPa−1 and 17.9 K GPa−1, respectively, which are 20 times higher than the traditional ferroelectric oxides such as BaTiO3 thin films. We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient (which could be realized through chemical doping, etc.). We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

Visible-light-promoted sulfonylation of thiols with aryldiazonium and sodium metabisulphite leading to unsymmetrical thiosulfonates

2021 ◽  
Author(s):  
Yu-Fen Lv ◽  
Jinyun Luo ◽  
Yuchuan Ma ◽  
Qi Dong ◽  
Lin He
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Metal Free ◽  
Sodium Metabisulphite ◽  
Three Component Reaction

A new visible-light-mediated protocol has been proposed for the synthesis of thiosulfonates via metal-free sulfonylation of thiols with aryldiazonium and sodium metabisulphite at room temperature. This mild three-component reaction, simply...

Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one

2019 ◽  
Vol 17 (2) ◽  
pp. 380-387 ◽  
Author(s):  
Shuai Zou ◽  
Shu Geng ◽  
Lina Chen ◽  
Haitao Wang ◽  
Feng Huang
Keyword(s):  
Visible Light ◽  
Intramolecular Cyclization ◽  
Facile Synthesis ◽  
Metal Free ◽  
Visible Light Driven

Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one.

Microwave irradiated synthesis of 2-bromo(chloro)indoles via intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in the presence of TBAF under metal-free conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 26918-26923 ◽  
Author(s):  
Min Wang ◽  
Pinhua Li ◽  
Wei Chen ◽  
Lei Wang
Keyword(s):  
Microwave Irradiation ◽  
Intramolecular Cyclization ◽  
Metal Free

2-Bromo(chloro)indoles were readily prepared through TBAF-promoted intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in excellent yields under metal-free and microwave irradiation conditions.

Diiiodine/Potassium Persulfate Mediated Synthesis of 1,2,3-Thiadiazoles from N-Tosylhydrazones and a Thiocyanate Salt as a Sulfur Source under Transition-Metal-Free Conditions

Synlett ◽  
2021 ◽  
Author(s):  
Yadong Sun ◽  
Ablimit Abdukader ◽  
Yuhan Lu ◽  
Chenjiang Liu
Keyword(s):  
Transition Metal ◽  
Efficient Method ◽  
Room Temperature ◽  
Functional Group ◽  
Ammonium Thiocyanate ◽  
Potassium Persulfate ◽  
Sulfur Source ◽  
Coupling Reactions ◽  
Wide Scope ◽  
Metal Free

AbstractA highly efficient method for the synthesis of 1,2,3-thiadiazoles has been developed by utilizing readily available tosylhydrazones and ammonium thiocyanate with ecofriendly EtOH as the solvent at room temperature. The reaction shows a wide scope of substrates and good functional-group tolerance. This protocol can be scaled up to a gram level and can be applied to coupling reactions with 4-(4-bromophenyl)-1,2,3-thiadiazole as the substrate.

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