629-01-6Relevant articles and documents
Ester ammoniolysis in an enzymatic membrane reactor
Luque, Susana,álvarez, José R.,Cuperus, F. Petrus
, p. 73 - 78 (2014)
A form of generating amides is by reaction of esters with ammonia (ammoniolysis) or with amines (aminolysis). This reaction can be catalyzed by free or immobilized lipases. The aim of this work is to develop a gas-liquid enzymatic membrane reactor in which the ammoniolysis of ethyl octanoate, catalyzed by Candida antarctica lipase B (EC 3.1.1.3), is improved through immobilization of the biocatalyst onto a membrane surface which also serves as gas-liquid interphase. After the selection of a suitable membrane for the process, data show that the higher the initial substrate concentration, the lower the reaction rate. A Michaelis-Menten type model with competitive product inhibition correlated well with the kinetic data. In addition, the temperature dependence of the reaction rate goes through a maximum. The yield of the amide was always above 92% in the range 25-55 °C, with a maximum of 95% at 40°C. At 40°C, and after 24 h of reaction, values comparable to those reported in the literature on the free enzyme-catalyzed ammoniolysis were achieved, but with much lower enzyme/substrate ratio. Moreover, the immobilized enzyme kept its activity for a long period of time (three weeks).
Ring Opening/Site Selective Cleavage in N-Acyl Glutarimide to Synthesize Primary Amides
Govindan, Karthick,Lin, Wei-Yu
supporting information, p. 1600 - 1605 (2021/03/03)
A LiOH-promoted hydrolysis selective C-N cleavage of twisted N-acyl glutarimide for the synthesis of primary amides under mild conditions has been developed. The reaction is triggered by a ring opening of glutarimide followed by C-N cleavage to afford primary amides using 2 equiv of LiOH as the base at room temperature. The efficacy of the reactions was considered and administrated for various aryl and alkyl substituents in good yield with high selectivity. Moreover, gram-scale synthesis of primary amides using a continuous flow method was achieved. It is noted that our new methodology can apply under both batch and flow conditions for synthetic and industrial applications.
One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
Coeck, Robin,De Vos, Dirk E.
supporting information, p. 5105 - 5114 (2020/08/25)
The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
