نتایج جستجو برای: friedel crafts alkylation

تعداد نتایج: 7394  

Journal: :Chemical science 2015
Ivana Drienovská Ana Rioz-Martínez Apparao Draksharapu Gerard Roelfes

Artificial metalloenzymes have emerged as an attractive new approach to enantioselective catalysis. Herein, we introduce a novel strategy for preparation of artificial metalloenzymes utilizing amber stop codon suppression methodology for the in vivo incorporation of metal-binding unnatural amino acids. The resulting artificial metalloenzymes were applied in catalytic asymmetric Friedel-Crafts a...

2013
Jiahuan Peng Da-Ming Du

The enantioselective tandem Friedel-Crafts alkylation/Michael addition reaction of indoles with nitroolefin enoates catalyzed by a diphenylamine-linked bis(oxazoline)-Zn(OTf)2 complex was investigated. This tandem reaction afforded functionalized chiral chromans in good yields with moderate to high stereoselectivities (up to 95:5 dr, up to 99% ee).

Journal: :The Journal of organic chemistry 2016
Guang-Jun Yang Wei Du Ying-Chun Chen

An asymmetric Friedel-Crafts alkylation reaction of 2-furfuryl ketones with β-trifluoromethyl enones has been developed via formal trienamine catalysis of a bifunctional primary amine-thiourea substance derived from L-tert-leucine, delivering the furan derivatives incorporating a stereogenic trifluoromethyl (CF3) group in good to high yields with excellent enantioselectivity.

The synthetic route in this work is based on the classical Friedel-Crafts strategy, and began with 1,4-dimethoxybenzene (I), followed by alkylation and selective demethylation of 2-methoxy function in 0x0-acid (3). The orthoformylation to synthesize aldehyde (6) was based on the Reimer-Tieman reaction. Chain extension of this aldehyde required methylation of the hydroxyl group and condensat...

Journal: :Organic & biomolecular chemistry 2010
Rik P Megens Gerard Roelfes

Water-miscible organic co-solvents can be used in DNA-based catalytic asymmetric reactions at appreciable concentration without a negative effect on enantioselectivity. While the rate of the copper(II) Diels-Alder reaction is affected negatively by the presence of organic co-solvents, the copper(II) catalyzed Michael addition and Friedel-Crafts alkylation reaction are significantly faster. Addi...

Journal: :Organic & biomolecular chemistry 2015
Yang Hu Lei Ju Lin Lu Hongmei Ma Xinhong Yu

We report a novel organocatalytic one-pot cascade bromination-Michael-type Friedel-Crafts alkylation dearomatization-nucleophilic rearrangement aromatization cascade process for the direct α-indolylation of unfunctionalized enals from readily available indoles with good yields and high E selectivity. The simplicity and practicality of its high efficiency for formation of a new C(sp(2))-C(sp(2))...

2016
Partha Samanta Priyanshu Chandra Sujit K Ghosh

Two hydroxy-functionalized hyper-cross-linked ultra-microporous compounds have been synthesized by Friedel-Crafts alkylation reaction and characterised with different spectroscopic techniques. Both compounds exhibit an efficient carbon dioxide uptake over other gases like N2, H2 and O2 at room temperature. A high isosteric heat of adsorption (Qst) has been obtained for both materials because of...

Journal: :Molecules 2017
Yi Zhu Ziwen Chen Zhenfei Huang Siwei Yan Zhuoer Li Hu Zhou Xiaokun Zhang Ying Su Zhiping Zeng

A classical Friedel-Crafts alkylation of different indoles catalyzed by AlCl₃·6H₂O has been developed for a well-known important natural product, celastrol, resulting in a series of derivatives for further biological evaluation. The catalyst loading was reduced to 5 mol %, the reaction proceeds at ambient temperature and reaction time is only 3 h. The product yields range from 20% to 99%. A rea...

Journal: :Angewandte Chemie 2017
Xiao-Long Xu Zhi Li

Allylation and benzylation of p-quinones was achieved through an unusual redox chain reaction. Mechanistic studies suggest that the existence of trace hydroquinone initiates a redox chain reaction that consists of a Lewis acid catalyzed Friedel-Crafts alkylation and a subsequent redox equilibrium that regenerates hydroquinone. The electrophiles could be various allylic and benzylic esters. The ...

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