37496-06-3Relevant academic research and scientific papers
Aroylation of Electron-Rich Pyrroles under Minisci Reaction Conditions
Laha, Joydev K.,Kaur Hunjan, Mandeep,Hegde, Shalakha,Gupta, Anjali
, p. 1442 - 1447 (2020/02/22)
The development of Minisci acylation on electron-rich pyrroles under silver-free neutral conditions has been reported featuring the regioselective monoacylation of (NH)-free pyrroles. Unlike conventional Minisci conditions, the avoidance of any acid that could result in the polymerization of pyrroles was the key to success. The umpolung reactivity of the nucleophilic acyl radical, generated in situ from arylglyoxylic acid, could help explain the mechanism of product formation with electron-rich pyrroles. Alternatively, the nucleophilic substitution of the acyl radical on the electron-deficient pyrrole radical cation is proposed.
Selective Methylation of Amides, N-Heterocycles, Thiols, and Alcohols with Tetramethylammonium Fluoride
Cheng, Hong-Gang,Pu, Maoping,Kundu, Gourab,Schoenebeck, Franziska
supporting information, p. 331 - 334 (2019/12/30)
We herein disclose the use of tetramethylammonium fluoride (TMAF) as a direct and selective methylating agent of a variety of amides, indoles, pyrroles, imidazoles, alcohols, and thiols. The method is characterized by operational simplicity, wide scope, and ease of purification. Our computational studies suggest a concerted methylation-deprotonation as the preferred reaction pathway.
A Novel and Chemoselective Process of N -Alkylation of Aromatic Nitrogen Compounds Using Quaternary Ammonium Salts as Starting Material
González-González, Carlos A.,Vega, Juan Javier Mejía,Monroy, Ricardo García,González-Calderón, Davir,Corona-Becerril, David,Fuentes-Benítes, Aydeé,Mascarúa, Joaquín Tamariz,González-Romero, Carlos
, (2018/02/28)
The process of N-alkylation of several pyrroles, indoles, and derivative heterocycles is herein described, using quaternary ammonium salts as the source of an alkylating agent. These reactions were carried out on several heterocyclic rings with triethylbenzylammonium chloride or tetradecyltrimethylammonium bromide and an NaOH solution at 50%, leading to a chemoselective N-alkylated product and an average yield of 73%. This is an alternative process to the traditional benzylation and methylation of N-heterocycles with direct handling of alkyl halides.
Synthesis of hetaryl-substituted 1,2,4-trithiolanes via a three-component reaction with dihetaryl thioketones, benzyl azide, and 2,2,4,4-tetramethyl-3-thioxocyclobutanone
Mlosto, Grzegorz,Celeda, Malgorzata,Linden, Anthony,Heimgartner, Heinz
, p. 14 - 22 (2016/02/12)
The three-component reactions with a hetaryl thioketone, 2,2,4,4-tetramethyl-3-thioxocyclobutanone, and excess benzyl azide performed at 60°C in the presence of LiClO4 lead to the formation of two types of 1,2,4-trithiolanes. As the major produ
Acylation of pyrroles and their free (N-H)-derivatives via palladium-catalyzed carbopalladation of nitriles
Jafarpour, Farnaz,Hazrati, Hamideh,Darvishmolla, Masoumeh
supporting information, p. 3784 - 3788 (2015/02/19)
An efficient regioselective synthesis of 2-acylpyrroles via palladium-catalyzed addition of pyrroles with benzonitriles and subsequent hydrolysis is developed. The direct acylation reaction of protected as well as (NH)-free pyrroles proceeded smoothly to
Solvent free synthesis of 2-acylpyrroles and its derivatives catalysed by reuseable zinc oxide
Zhang, Shuguang,Feng, Chengliang,Cai, Jin,Chen, Junqing,Hu, Huayou,Ji, Min
, p. 480 - 482 (2013/09/12)
A highly efficient procedure for preparing 2-acylpyrroles and its derivatives is described. The products were obtained through regioselective Friedel-Crafts reactions of pyrroles and its derivatives with alkyl or aryl acid chlorides catalysed by zinc oxide under solvent-free conditions. This method has the advantages of green chemistry, operational simplicity, solvent-free conditions, and recoverable catalyst.
Iodide as an activating agent for acid chlorides in acylation reactions
Wakeham, Russell J.,Taylor, James E.,Bull, Steven D.,Morris, James A.,Williams, Jonathan M. J.
supporting information, p. 702 - 705 (2013/04/11)
Acid chlorides can be activated using a simple iodide source to undergo nucleophilic attack from a variety of relatively weak nucleophiles. These include Friedel-Crafts acylation of N-methylpyrroles, N-acylation of sulfonamides, and acylation reactions of hindered phenol derivatives. The reaction is believed to proceed through a transient acid iodide intermediate.
Friedel - Crafts acylation of pyrroles and indoles using 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) as a nucleophilic catalyst
Taylor, James E.,Jones, Matthew D.,Williams, Jonathan M. J.,Bull, Steven D.
supporting information; experimental part, p. 5740 - 5743 (2011/03/18)
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) has been shown to be an effective catalyst for the regioselective Friedel - Crafts C-acylation of pyrroles and indoles in high yields. A detailed mechanistic study implies that DBN is acting as a nucleophilic organocatalyst, with the X-ray crystal structure of a key N-acyl-amidine intermediate having been determined for the first time.
Unexpectedly high activity of Zn(OTf)2·6H2O in catalytic Friedel-Crafts acylation reaction
He, Fei,Wu, Huayue,Chen, Jiuxi,Su, Weike
, p. 255 - 264 (2008/03/17)
Zn(OTf)2·6H2O was used to promote Friedel-Crafts acylation of aromatics. The work describes the high activity and efficiency of Zn(OTf)2·6H2O in acylation of aromatics, and the catalyst has surpassed most metal triflates in dispensing when dried at high temperature under vacuum before use. Copyright Taylor & Francis Group, LLC.
Ytterbium (III) trifluoromethanesulfonate catalysed Friedel-Crafts acylation of 1-methylpyrrole in ionic liquid
Su, Weike,Wu, Chunlei,Su, Hao
, p. 67 - 68 (2007/10/03)
In the presence of a catalytic amount of ytterbium (III) trifluoromethanesulfonate [Yb(OTf)3], 1-methylpyrrole can easily react with acyl chlorides in an ionic liquid [bpy][BF4](bpy=1- butylpyridine) to form corresponding ketones in satisfactory yield. The recyclability of the ionic liquid/catalyst system is demonstrated.
