- Catalytic Alkylation Using a Cyclic S-Adenosylmethionine Regeneration System
-
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.
- Mordhorst, Silja,Siegrist, Jutta,Müller, Michael,Richter, Michael,Andexer, Jennifer N.
-
supporting information
p. 4037 - 4041
(2017/03/27)
-
- Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
-
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.
- 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)
-
- Synthesis of 1-substituted 4(1H)-quinazolinones under solvent-free conditions
-
(Chemical Equation Presented) Heating a mixture of 2-(N-alkylamino)benzoic acids, triethyl orthoformate, and ammonium acetate under solvent-free conditions generated 1-substituted 4(1H)- quinazolinones in 73-99% yields. Moreover, a possible reaction pathway was proposed. Copyright Taylor & Francis Group, LLC.
- Wang, Yao,Zhang, Mei,Cao, Shengli,Lin, Huihui,Gao, Man,Li, Zhongfeng
-
p. 2715 - 2727
(2012/07/14)
-
- Efficient copper-catalyzed synthesis of N-alkylanthranilic acids via an ortho-substituent effect of the carboxyl group of 2-halobenzoic acids at room temperature
-
We have developed an efficient copper-catalyzed method for the synthesis of N-alkylanthranilic acids. The protocol uses inexpensive copper(I) iodide/racemic 1,1'-binaphthyl-2,2'-diol (rac-BINOL) as the catalyst/ligand system, readily available 2-halobenzoic acids and aliphatic amines as the starting materials, the coupling reactions were performed at room temperature, and various functionalities in the substrates were tolerated.
- Zeng, Liang,Fu, Hua,Qiao, Renzhong,Jiang, Yuyang,Zhao, Yufen
-
supporting information; experimental part
p. 1671 - 1676
(2011/02/25)
-
- Ultrasound-promoted reaction of 2-chlorobenzoic acids and aliphatic amines
-
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.
- Docampo, Maite L.,Pellon, Rolando F.,Estevez-Braun, Ana,Ravelo, Angel G.
-
p. 4111 - 4115
(2008/02/13)
-
- Use of ultrasound in the synthesis of 2-(alkylamino)benzoic acids in water
-
The synthesis of substituted 2-(alkylamino)benzoic acids using the Ullmann condensation with water as the solvent and utilizing ultrasound irradiation was achieved with high yields in a short reaction time. Georg Thieme Verlag Stuttgart.
- Pellón, Rolando F.,Estévez-Braun, Ana,Docampo, Maite L.,Martín, Ana,Ravelo, Angel G.
-
p. 1606 - 1608
(2007/10/03)
-
- Reductive and catalytic monoalkylation of primary amines using nitriles as an alkylating reagent
-
(Chemical Equation Presented) A selective and catalytic mono-N-alkylation method of both aromatic and aliphatic amines using nitriles as an alkylating agent with Pd/C or Rh/C as a catalyst is described. This method is particularly attractive to provide an environmentally benign and applicable alkylation method of amines without using toxic and corrosive alkylating agents such as alkyl halides and carbonyl compounds.
- Sajiki, Hironao,Ikawa, Takashi,Hirota, Kosaku
-
p. 4977 - 4980
(2007/10/03)
-
- Synthesis of mono-N-substituted functionalized anilines
-
The present invention relates to a process for direct and selective synthesis of mono-N-substituted functionalized anilines by using alkylating agents selected from the class of organic carbonates, preferably of the dialkyl, dibenzyl and diallyl types, in the presence of suitable catalysts that are chemically related to the class of aluminosilicates.
- -
-
-
- Synthesis of mono-N-substituted functionalized anilines
-
The present invention relates to a process for direct and selective synthesis of mono-N-substituted functionalized anilines by using alkylating agents selected from the class of organic carbonates, preferably of the dialkyl, dibenzyl and diallyl types, in the presence of suitable catalysts that are chemically related to the class of aluminosilicates.
- -
-
-
- Kinetics and mechanism of the homogeneous oxidation of quinaldine red by hydrogen peroxide
-
The kinetics of the oxidation of quinaldine red, a cationic dye, using hydrogen peroxide has been studied in aqueous solution. The rate of reaction was found to be first order in [quinaldine red] whereas in hydrogen peroxide it varies from one to zero with increasing [H2O2]. The rate of reaction increases with increasing pH as well as with the addition of sodium carbonate. The reaction rate attains a limiting value at higher carbonate concentrations which is attributed to the maximum formation of peroxide anions. The rate of hydrogen peroxide decomposition in the presence of sodium carbonate is much greater than that of bleaching of the dye under the same conditions. Moreover, the rate of reaction decreases with increasing ionic strength suggesting an interaction between two singly oppositely charged ions in the activated complex. A plausible reaction mechanism is proposed with a rate equation that is in agreement with the experimental data. by Oldenbourg Wissenschaftsverlag, Muenchen.
- Salem, Ibrahim A.,El-Maazawi, Mohamed
-
p. 623 - 636
(2007/10/03)
-
- 4-Hydroxy-2-quinolones. 37. Simple synthesis of 1-R-2-oxo-3,4-dihydroxyquinolines
-
3-Amino-1-R-2-oxo-4-hydroxyquinolines easily undergo acid hydrolysis with formation of the corresponding 1-R-2-oxo-3,4-dihydroxyquinolines. 1998 Plenum Publishing Corporation.
- Ukrainets,Taran,Sidorenko,Gorokhova
-
p. 1334 - 1336
(2007/10/03)
-