نتایج جستجو برای: fluorinated enones

تعداد نتایج: 4816  

Journal: :Chemical communications 2011
Avgousta Ioannou Elena Cini Roxana S Timofte Sabine L Flitsch Nicholas J Turner Bruno Linclau

Galactose oxidase (GOase) was shown to oxidise several C2/C3 fluorinated galactose analogues. Interestingly, the enzyme was able to distinguish between the 2,3-tetrafluorinated galactose and its epimeric glucose analogue, and this represents the first reported biotransformation of a heavily fluorinated sugar.

Journal: :Chemistry 2014
Ran-Ning Guo Xian-Feng Cai Lei Shi Zhang-Pei Chen Yong-Gui Zhou

An efficient and transition-metal-free approach was developed to access a series of fluorinated heteroaromatics in moderate to excellent yields. This one-pot procedure features a triple-relay transformation of rapid dearomatization, fluorination, and rearomatization processes, which represents a conceptually novel strategy of combining partial hydrogenation and electrophilic fluorination.

2012
Guang Chen Bin Wei Bruce E. Logan Michael A. Hickner

Fluorinated quaternary ammonium-containing polymers were used as catalyst binders in microbial fuel cell (MFC) cathodes. The performance of the cathodes was examined and compared to NAFION and other sulfonated aromatic cathode catalyst binders using linear sweep voltammetry (LSV), impedance spectroscopy, and performance tests in single chamber air-cathode MFCs. The cathodes with quaternary ammo...

Journal: :Journal of oleo science 2014
Kenichi Sakai Naoki Umemoto Kenichi Aburai Yuichiro Takamatsu Takeshi Endo Boonyarach Kitiyanan Mutsuyoshi Matsumoto Hideki Sakai Masahiko Abe

We have developed oleic acid-based partially fluorinated gemini surfactants with carboxylic acid headgroups. The fluorocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via a -CH(2)CH(2)OCO- unit, and the carboxylic acid headgroups are introduced to the cis double bond of oleic acid via -OCOCH(2)CH(2)- units. The aqueous solution properties of these surfactants were ...

Journal: :Organic letters 2013
Shaojin Chen Lin Hao Yuexia Zhang Bhoopendra Tiwari Yonggui Robin Chi

An NHC-catalyzed activation of acetic esters to afford enolate intermediates is disclosed. The catalytically generated triazolium enolate intermediates serve as two-carbon nucleophiles that undergo highly enantioselective reactions with enones and α,β-unsaturated imines to give α-unsubstituted δ-lactones and lactams, respectively.

Journal: :Organic & biomolecular chemistry 2011
Paul D Thornton T Stanley Cameron D Jean Burnell

Tandem oxy-Cope and transannular vinylogous aldol reactions and/or vinylogous retro-aldol, conjugate addition, and transannular vinylogous aldol reactions transformed some tricyclic vinyl enones into fused tetracycles under basic conditions. Mesylates derived from similar tetracyclic products underwent efficient skeletal reorganization via transannular ring-opening but then different modes of t...

Journal: :Organic letters 2000
Ge Stoltz Corey

We adduce evidence that the asynchronous, Lewis acid-catalyzed Diels-Alder reaction of 2-cycloalkenones with nonsimple alpha,beta-enones can proceed via transition states in which the 1,3-diene subunit is skewed, i.e., nonplanar, with profound effects on the ratio of exo and endo addition products.

Journal: :Organic & biomolecular chemistry 2010
Vincent Gembus Jean-Jacques Bonnet François Janin Pierre Bohn Vincent Levacher Jean-François Brière

The elaboration of biologically important 3,4-substituted pyrazolines was achieved by an organocatalysed aza-Michael/transimination domino sequence between hydrazones and enones making use of a mixture of heterogeneous resin-bound acid/base reagents. This methodology nicely illustrates the site isolation concept of supported reagents allowing the simultaneous use of otherwise destructive reacti...

2016
Christopher Clarke Celia A. Incerti-Pradillos Hon Wai Lam

Nickel-catalyzed additions of arylboronic acids to alkynes, followed by enantioselective cyclizations of the alkenylnickel species onto tethered ketones or enones, are reported. These reactions are reliant upon the formal anti-carbonickelation of the alkyne, which is postulated to occur by the reversible E/Z isomerization of an alkenylnickel species.

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.

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