fulltext.study @t Gmail

Brönsted acid ionic liquids catalyzed Friedel–Crafts Alkylations of electron-rich arenes with aldehydes

Paper ID Volume ID Publish Year Pages File Format Full-Text
39600 45828 2014 7 PDF Available
Title
Brönsted acid ionic liquids catalyzed Friedel–Crafts Alkylations of electron-rich arenes with aldehydes
Abstract

•Brönsted acid ionic liquids (BAILs) were designed and synthesized.•BAILs can be used for catalyzing Friedel–Crafts Alkylations successfully.•[HSO3-pmim][OTf] shows higher catalytic activity.•BAILs can be recycled without noticeably decreasing the catalytic activity.

Triarylmethanes (TRAMs) and diarylalkanes (DIAAs) are valuable intermediates with wide applications in many fields. TRAMs are usually obtained from the acid-catalysed bisarylation of activated aryl aldehydes. However, the synthesis poses many problems, such as harsh reaction conditions, and the disposal of the excess solvents and/or toxic metal waste. In this study, some functionalized ionic liquids including Brönsted acid ionic liquids (BAILs) and traditional ionic liquids were designed and synthesized. BAILs catalyzed Friedel–Crafts (F–C) alkylation was applied in this specific reaction for the first time. And the BAILs showed bifunctional properties acting as catalyst and solvent. Research shows that BAILs can be used for catalyzing F–C alkylations of electron-rich arenes with aromatic or aliphatic aldehydes successfully under mild reaction conditions. Furthermore, BAILs containing triflic anion has higher activity than other BAILs and traditional ionic liquids. [HSO3-pmim][OTf] gets the highest yields in the presence of 20 mol% of BAILs at 40 °C to give the corresponding TRAMs derivatives. After five cycles, the yields remain about 93–97%. Finally, according to IR spectrum and the experimental validation, the aromatic electrophilic substitution reaction was considered to be the possible catalysis mechanisms.

Graphical abstractIn this study, some functionalized ionic liquids including Brönsted acid ionic liquids (BAILs) and traditional ionic liquids were designed and synthesized. BAILs catalyzed Friedel–Crafts (F–C) alkylation was applied in this specific reaction. Research shows that BAILs can be used for catalyzing F–C alkylations of electron-rich arenes with aromatic or aliphatic aldehydes successfully. After five cycles, the yields remain about 93–97% and without noticeably decreasing the catalytic activity.Figure optionsDownload full-size imageDownload high-quality image (68 K)Download as PowerPoint slide

Keywords
Triarylmethane; Functionalized ionic liquids; Friedel–Crafts; Alkylation; Aldehydes
First Page Preview
Brönsted acid ionic liquids catalyzed Friedel–Crafts Alkylations of electron-rich arenes with aldehydes
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 482, 22 July 2014, Pages 198–204
Authors
, , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis