25038-74-8Relevant articles and documents
Enzyme-catalyzed laurolactam synthesis via intramolecular amide bond formation in aqueous solution
Ladkau, Nadine,Hermann, Inna,Buehler, Bruno,Schmid, Andreas
, p. 2501 - 2510 (2011)
Lactam formation from ω-aminocarboxylic acids is thermodynamically unfavored in aqueous solution and therefore hard to achieve. In the present work ω-laurolactam hydrolases from Acidovorax sp. T31 and Cupriavidus sp. U124 were investigated regarding their potential to catalyze lactam formation. Both enzymes are known to hydrolyze laurolactam to 12-aminododecanoic acid. The ω-laurolactam hydrolase genes were expressed in Escherichia coli BL21 (DE3) and the catalytic activity of the respective proteins was investigated. As expected from thermodynamics, only laurolactam hydrolysis but not 12-aminododecanoic acid cyclization was observed in whole-cell biotransformations and cell extract assays. The utilization of 12-aminododecanoic acid methyl ester, as an activated form of 12-aminododecanoic acid, resulted in intramolecular amide bond formation with the product laurolactam. Maximum laurolactam formation rates of 13.5 and 14.3 U g CDW-1 and molar yields of 11.5% and 13.0% were achieved in biotransformations at pH 10 with recombinant E. coli harboring the ω-laurolactam hydrolase from Cupriavidus sp. U124 and Acidovorax sp. T31, respectively. Furthermore, it was shown that under the harsh reaction conditions applied, the utilization of whole-cell biocatalysts enables 17.2-fold higher laurolactam formation activity in comparison to free enzymes in solution. This study shows that hydrolase-catalyzed laurolactam synthesis can be achieved in aqueous solution by selection of an appropriate substrate and reaction pH. Copyright
In situ multinuclear solid-state NMR spectroscopy study of Beckmann rearrangement of cyclododecanone oxime in ionic liquids: The nature of catalytic sites
Blasco,Corma,Iborra,Lezcano-Gonzalez,Monton
, p. 78 - 83 (2010)
The Beckmann rearrangement of cyclododecanone oxime into ω-laurolactam has been investigated in four ionic liquids: 1-butyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate ([C4mim], [C4mim]), and 1-butyl-2,3-dimethylimidazolium and 1-butyl-4-methylpyridinium hexafluorophosphates ([C4mpyr], [C4m2im]), in a batch reactor as well as by 'in situ' multinuclear solid-state NMR spectroscopy. The Beckmann rearrangement reaction of cyclododecanone oxime takes place in [C4mim] and [C4mpyr] with excellent activity and selectivity, while practically null activity is observed in [C4m2im] and [C4mim]. The results obtained indicate that a very low level of hydrolysis of the PF6- anion in [C4mim] and [C4mpyr] occurs under reaction conditions (130 °C), and the HF formed at the level of ppm acts as catalyst in the Beckmann rearrangement with excellent conversion and selectivity.
Dehydrative Beckmann rearrangement and the following cascade reactions
Liu, Yinghui,Wei, Yongjiao,Xie, Lan-Gui
supporting information, (2021/11/16)
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
Efficient nitriding reagent and application thereof
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Paragraph 0420-0423, (2021/03/31)
The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
