Metal-free regioselective C–H chalcogenylation of coumarins/(hetero)arenes at ambient temperature

2020 ◽  
Vol 56 (12) ◽  
pp. 1847-1850
Author(s):  
Zengqiang Song ◽  
Chaochao Ding ◽  
Shaoli Wang ◽  
Qian Dai ◽  
Yaoguang Sheng ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Room Temperature ◽  
Practical Method ◽  
Metal Free

A novel and practical method for the direct regioselective chalcogenylation of coumarins at the C3-postion and selenation of other (hetero)arenes has been achieved using PIFA as a promoter at room temperature.

Room Temperature, Metal-Free, Regio-Selective Arylselenation of Anilines Using Diselenides as Selenium Source

Synthesis ◽  
2022 ◽  
Author(s):  
Rekha Bai ◽  
Kamlesh Kumar Dabaria ◽  
Satpal Singh Badsara
Keyword(s):  
Ambient Temperature ◽  
Room Temperature ◽  
Bond Formation ◽  
Metal Free ◽  
Aniline Derivatives

A metal-free direct C-H selenation of aniline derivatives via an iodine catalysed C-Se bond formation using diselenides as a selenium source at ambient temperature is described. A variety of aniline derivatives underwent regio-selective C-H selenation with different diselenides to afford the corresponding aryl selenoethers in good to excellent yields.

Sulfonamide formation from sodium sulfinates and amines or ammonia under metal-free conditions at ambient temperature

2015 ◽  
Vol 17 (3) ◽  
pp. 1395-1399 ◽  
Author(s):  
Kai Yang ◽  
Miaolin Ke ◽  
Yuanguang Lin ◽  
Qiuling Song
Keyword(s):  
Ambient Temperature ◽  
Efficient Method ◽  
Room Temperature ◽  
Metal Base ◽  
Metal Free ◽  
Highly Efficient ◽  
Reaction Proceeds

A practical and highly efficient method for the construction of a variety of sulfonamides mediated by I2 was demonstrated. The reaction proceeds readily at room temperature using a variety of sodium sulfinates and amines or ammonia in water in a metal-, base-, ligand-, or additive-free protocol. Primary, secondary and tertiary sulfonamides were obtained in good to excellent yields with a broad range of substrate tolerability.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

scholarly journals Practical Synthesis of 2-Iodosobenzoic Acid (IBA) without Contamination by Hazardous 2-Iodoxybenzoic Acid (IBX) under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Practical Method ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Sequential Procedures ◽  
Iodine Compounds ◽  
Practical Synthesis ◽  
Iodosobenzoic Acid ◽  
Lower Temperature

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.

Transition metal free, green and facile halogenation of ketene dithioacetals using a KX–oxidant system

2021 ◽  
Author(s):  
Vishakha Rai ◽  
Ganesh Shivayogappa Sorabad ◽  
Mahagundappa Rachappa Maddani
Keyword(s):  
Transition Metal ◽  
Ambient Temperature ◽  
Metal Free ◽  
Ketene Dithioacetals ◽  
System P ◽  
Oxidative Halogenation ◽  
Potassium Halide

A facile oxidative halogenation of α-oxo ketene dithioacetals is achieved by using a potassium halide and an oxidant combination under transition metal free conditions at ambient temperature.

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...

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.

Sign in / Sign up

Export Citation Format

Share Document