89-50-9Relevant articles and documents
Catalytic Alkylation Using a Cyclic S-Adenosylmethionine Regeneration System
Mordhorst, Silja,Siegrist, Jutta,Müller, Michael,Richter, Michael,Andexer, Jennifer N.
supporting information, p. 4037 - 4041 (2017/03/27)
S-Adenosylmethionine-dependent methyltransferases are versatile tools for the specific alkylation of many compounds, such as pharmaceuticals, but their biocatalytic application is severely limited owing to the lack of a cofactor regeneration system. We report a biomimetic, polyphosphate-based, cyclic cascade for methyltransferases. In addition to the substrate to be methylated, only methionine and polyphosphate have to be added in stoichiometric amounts. The system acts catalytically with respect to the cofactor precursor adenosine in methylation and ethylation reactions of selected substrates, as shown by HPLC analysis. Furthermore, 1H and 13C NMR measurements were performed to unequivocally identify methionine as the methyl donor and to gain insight into the selectivity of the reactions. This system constitutes a vital stage in the development of economical and environmentally friendly applications of methyltransferases.
Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
Ikawa, Takashi,Fujita, Yuki,Mizusaki, Tomoteru,Betsuin, Sae,Takamatsu, Haruki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
supporting information; experimental part, p. 293 - 304 (2012/02/01)
Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH4OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.
Ultrasound-promoted reaction of 2-chlorobenzoic acids and aliphatic amines
Docampo, Maite L.,Pellon, Rolando F.,Estevez-Braun, Ana,Ravelo, Angel G.
, p. 4111 - 4115 (2008/02/13)
An improvement to the use of DMF as a solvent for the condensation of 2-chlorobenzoic acids with aliphatic primary or secondary amines was described. A number of alkylaminobenzoic acids and dialkylaminobenzoic acids were synthesized in acceptable-to-good yield. The advantages of this procedure include readily available substrates, the use of an inexpensive copper powder without taking any precautions to exclude moisture under mild conditions and experimental ease. Furthermore, this condensation could also be achieved under nonclassical conditions by using ultrasonic irradiation at room temperature. We demonstrated that ultrasound-promoted condensation of 2-chlorobenzoic acid with aliphatic amines with the use of DMF as the solvent, especially in the case of secondary amines, affords products in high yields and reduces the reaction time to minutes. The results proved to be highly reproducible because the relevant sonochemical parameters were rigorously controlled. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
