92-54-6Relevant articles and documents
Eco-friendly synthesis of ionic helical polymers and their chemical properties and reactivity
Yamaguchi, Isao,Tanaka, Yuki,Wang, Aohan
, p. 29988 - 29994 (2018)
Reaction of N-(2,4-dinitrophenyl)pyridinium chloride (salt(Cl-)) with sodium dicyanamide (Na(CN)2N) resulted in anion exchange between Cl- and (CN)2N- to yield a new Zincke salt, salt((CN)2N-). Reactions of salt((CN)2N-) with piperazine, specifically (R)-(-)- or (S)-(+)-2-methylpiperazine under eco-friendly conditions, such as in aqueous solution, in the absence of a catalyst, and at room temperature, resulted in pyridinium ring opening to yield ionic high-molecular-weight polymers with 5-2,4-dienylideneammonium dicyanamide units or chiral 5-(2-methylpiperazinium)-2,4-dienylideneammonium dicyanamide units, namely, polymer(H;(CN)2N-), polymer(R-Me;(CN)2N-), and polymer(S-Me;(CN)2N-). UV-Vis measurements revealed that the π-conjugation system expanded along the polymer chain due to the orbital interaction between the electrons on the two nitrogen atoms of the piperazinium ring. Circular dichroism (CD) measurements revealed a helical conformation of the main chain in polymer(R-Me;(CN)2N-) and polymer(S-Me;(CN)2N-). The reaction of polymer(H;(CN)2N-) with p-phenylenediamine (PDA) caused recyclization of the 2,4-dienylideneammonium unit and resulted in depolymerization to yield N-(4-aminophenyl)pyridinium dicyanamide. Cyclic voltammetry analysis suggested that the polymers obtained in this study undergo electrochemical oxidation and reduction.
Indirect reduction of CO2and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes
Liu, Xin,Werner, Thomas
, p. 10590 - 10597 (2021/08/20)
The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives, and even polyurethanes leading to the corresponding alcohols, amines, and methanol as products. Since these compound classes can be prepared using CO2as a C1 building block the reported reaction represents an approach to the indirect reduction of CO2. Notably, these are the first examples on the reduction of carbamates and urea derivatives as well as on the C-N bond cleavage in amides by transfer hydrogenation. The general applicability of this methodology is highlighted by the successful reduction of 12 urea derivatives, 26 carbamates and 11 amides. The corresponding amines, alcohols and methanol were obtained in good to excellent yields up to 97%. Furthermore, polyurethanes were successfully converted which represents a viable strategy towards a circular economy. Based on control experiments and the observed intermediates a feasible mechanism is proposed.
MONOACYLGLYCEROL LIPASE INHIBITORS
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, (2021/09/09)
Provided are compounds of formula (I), or a pharmaceutically acceptable salt or solvate thereof: Also provided are compositions comprising compounds of formula (I). The compounds and compositions are also provided for use as medicaments, for example as medicaments useful in the treatment of a condition modulated by monoacylglycerol lipase (MAGL). Also provided are the use of compounds and compositions for the inhibition of monoacylglycerol lipase (MAGL).
