109-46-6Relevant articles and documents
Malonic Acid Derivatives on Duty as Electron-Withdrawing Units in Push–Pull Molecules
Klikar, Milan,Jelínková, Veronika,R??i?ková, Zdeňka,Mikysek, Tomá?,Pytela, Old?ich,Ludwig, Miroslav,Bure?, Filip
, p. 2764 - 2779 (2017)
Based on the 2-(N-piperidinyl)thiophene central donor, 32 model push–pull molecules with systematically varied malonic acid-derived peripheral acceptors have been prepared. Further property tuning has been achieved by modifying the π-linker and the structural arrangement (linear vs. quadrupolar D–π–A systems). Malonic acid derivatives such as cyanoacetic acid, malondinitrile, diethyl malonate, Meldrum′s acid, and N,N′-dibutyl(thio)barbituric acid as well as 1,3-diketo analogues dimedone and indan-1,3-dione were employed as acceptor moieties. Knoevenagel condensation with four thiophene aldehydes afforded the target chromophores in satisfactory yields. The electron-withdrawing abilities of malonic acid acceptors were examined both by experiment including X-ray analysis, differential scanning calorimetry, electrochemistry, and UV/Vis absorption spectroscopy, and by DFT calculations. Details of the structure–property relationships have been elucidated. According to the increasing electron-withdrawing ability, the widely used malonic acid acceptor units can be ordered: diethyl malonate ≤ cyanoacetic acid malondinitrile Meldrum's acid dimedone ≤ N,N′-dibutylbarbituric acid indan-1,3-dione ≤ N,N′-dibutylthiobarbituric acid.
Synthesis of novel dithiocarbamates and xanthates using dialkyl azodicarboxylates: S–N bond formation
Ziyaei Halimehjani, Azim,Klepetá?ová, Blanka,Beier, Petr
, p. 1850 - 1858 (2018/03/06)
A one?pot three?component route for the synthesis of a novel category of dithiocarbamates or xanthates is developed by a reaction of in-situ generated dithiocarbamic acids or xanthates with dialkyl azodicarboxylates under mild and catalyst-free conditions. The reaction is characterized by a wide scope, high efficiency and straightforward isolation protocol. The synthetic utility of the dithiocarbamates and xanthates was demonstrated on the preparation of symmetrical and unsymmetrical thioureas, isothiocyanates, and thiocarbamates.
Rapid and highly efficient synthesis of thioureas in biocompatible basic choline hydroxide
Azizi, Najmedin,Farhadi, Elham
, p. 548 - 554 (2017/09/27)
A straightforward and convenient synthesis of symmetrical thiourea derivatives by the reaction of primary amines and carbon disulfide in biocompatible basic choline hydroxide is presented. A variety of biologically important thiourea derivatives can be obtained in good to excellent yields without a tedious work-up under mild reaction conditions. A series of primary aliphatic and aromatic amines with different substituted functional groups have been converted to thiourea derivatives under milder reaction conditions and short reaction times.