5261-18-7Relevant academic research and scientific papers
Damage and Repair in Informational Poly(N-substituted urethane)s
Charles, Laurence,Lutz, Jean-Fran?ois,Mondal, Tathagata
supporting information, p. 20390 - 20393 (2020/09/21)
The degradation and repair of uniform sequence-defined poly(N-substituted urethane)s was studied. Polymers containing an ω-OH end-group and only ethyl carbamate main-chain repeat units rapidly degrade in NaOH solution through an ω→α depolymerization mechanism with no apparent sign of random chain cleavage. The degradation mechanism is not notably affected by the nature of the side-chain N-substituents and took place for all studied sequences. On the other hand, depolymerization is significantly influenced by the molecular structure of the main-chain repeat units. For instance, hexyl carbamate main-chain motifs block unzipping and can therefore be used to control the degradation of specific sequence sections. Interestingly, the partially degraded polymers can also be repaired; for example by using a combination of N,N′-disuccinimidyl carbonate with a secondary amine building-block. Overall, these findings open up interesting new avenues for chain-healing and sequence editing.
Novelty of immobilized enzymatic synthesis of 3-ethyl-1,3-oxazolidin-2-one using 2-aminoalcohol and dimethyl carbonate: Mechanism and kinetic modeling of consecutive reactions
Yadav, Ganapati D.,Pawar, Sandip V.
, p. 62 - 69 (2014/11/08)
Oxazolidinones are multifunctional compounds possessing diverse biological and pharmacological activity. Enzymatic synthesis of oxazolidin-2-one was studied using 2-aminoalochol and dimethyl carbonate and synthesis of 3-ethyl-1,3-oxazolidin-2-one was chosen as the model reaction using a variety of immobilized lipases; among which Candida antarctica lipase B (Novozyme 435) was the best catalyst. The reaction leads to the final product oxazolidin-2-one via methyl ethyl (2-hydroxyethyl) carbamate as the intermediate. The parameters affecting rate of reaction and the conversion of both steps were studied systematically and covered effects of agitation speed, solvent, catalyst loading and reaction temperature. A reaction mechanism was proposed wherein the coproduct methanol is generated in the first step leading to the formation of methyl ethyl (2-hydroxyethyl) carbamate as the intermediate which rearranges itself leading to the final products 3-ethyl-1,3-oxazolidin-2-one and methanol. The kinetic constant and activation energy were determined for each step of the reaction. The study was further extended to other 2-aminoalochols under optimized reaction conditions to prepare different oxazolidinones. This is a first report of its kind describing kinetics and mechanism of bimolecular consecutive enzyme catalyzed reactions.
