Metal free amination of congested and functionalized alkyl bromides at room temperature

2020 ◽  
Vol 56 (35) ◽  
pp. 4804-4807
Author(s):  
Arshad J. Ansari ◽  
Ayushi Yadav ◽  
Anirban Mukherjee ◽  
Elagandhula Sathish ◽  
Kommu Nagesh ◽  
...  

A metal free approach to access congested aryl amines using aza-oxyallyl cations as electrophiles has been reported. The given method could readily be adapted for the synthesis of coveted 3,5-benzodizepinones.

Author(s):  
Ruisheng Liu ◽  
Qishun Liu ◽  
Haoran Meng ◽  
Hongyu Ding ◽  
Jindong Hao ◽  
...  

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.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ramanshu P. Singh ◽  
Shakti Yadav ◽  
Giridhar Mishra ◽  
Devraj Singh

Abstract The elastic and ultrasonic properties have been evaluated at room temperature between the pressure 0.6 and 10.4 GPa for hexagonal closed packed (hcp) hafnium (Hf) metal. The Lennard-Jones potential model has been used to compute the second and third order elastic constants for Hf. The elastic constants have been utilized to calculate the mechanical constants such as Young’s modulus, bulk modulus, shear modulus, Poisson’s ratio, and Zener anisotropy factor for finding the stability and durability of hcp hafnium metal within the chosen pressure range. The second order elastic constants were also used to compute the ultrasonic velocities along unique axis at different angles for the given pressure range. Further thermophysical properties such as specific heat per unit volume and energy density have been estimated at different pressures. Additionally, ultrasonic Grüneisen parameters and acoustic coupling constants have been found out at room temperature. Finally, the ultrasonic attenuation due to phonon–phonon interaction and thermoelastic mechanisms has been investigated for the chosen hafnium metal. The obtained results have been discussed in correlation with available findings for similar types of hcp metals.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cheng Li ◽  
Yu Hui Huang ◽  
Jian-Jun Wang ◽  
Bo Wang ◽  
Yong Jun Wu ◽  
...  

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.


Author(s):  
Yu-Fen Lv ◽  
Jinyun Luo ◽  
Yuchuan Ma ◽  
Qi Dong ◽  
Lin He

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...


2021 ◽  
Author(s):  
Matthew Wheatley ◽  
Michael T. Findlay ◽  
Rocío López-Rodríguez ◽  
Diego M. Cannas ◽  
Marco Simonetti ◽  
...  

2015 ◽  
Vol 17 (2) ◽  
pp. 893-897 ◽  
Author(s):  
Nicholas A. Isley ◽  
Matt S. Hageman ◽  
Bruce H. Lipshutz

Alkyl bromides and chlorides can be reduced to the corresponding hydrocarbons utilizing zinc in the presence of an amine additive under very mild, green conditions.


Synlett ◽  
2021 ◽  
Author(s):  
Yadong Sun ◽  
Ablimit Abdukader ◽  
Yuhan Lu ◽  
Chenjiang Liu

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.


2021 ◽  
Author(s):  
Hui Liu ◽  
Chao Liu ◽  
Shanyi Chen ◽  
Qihong Lai ◽  
Yulin Lin ◽  
...  

An efficient method for the direct oxidative lactonization of the C(sp3)–H bonds of benzyl via visible-light-induced photoredox catalysis. The metal-free protocol delivers diverse phthalides using O2 as the sole terminal oxidant at room temperature.


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