نتایج جستجو برای: Fluorination

تعداد نتایج: 1361  

2017
Tsukasa Furuya Takashi Nomoto Tsuyoshi Fukuhara Shoji Hara

We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

Journal: :Chemistry 2015
Steven Bloom Desta Doro Bume Cody Ross Pitts Thomas Lectka

To expand upon the recent pioneering reports of catalyzed sp(3) C-H fluorination methods, the next rational step is to focus on directing "radical-based fluorination" more effectively. One potential solution entails selective C-C bond activation as a prelude to selective fluorination. Herein, we report the tandem photocatalyzed ring-opening/fluorination reactions of cyclopropanols by 1,2,4,5-te...

Journal: :Journal of colloid and interface science 2009
Sangyun A Lee Sang Hyup Oh Woojin Lee

To investigate the effect of fluorination on the surface of polydimethylsiloxane (PDMS) film, direct fluorination was performed under a mild condition (approx. 2000 micromol/mol F(2) in nitrogen) for 120 min. No structural damage of PDMS films was observed on the scanning electron microscopic images under the condition. Fourier-transform infrared/attenuated total reflectance (FTIR/ATR) and ener...

Journal: :Journal of the American Chemical Society 2017
Cody Ross Pitts Desta Doro Bume Stefan Andrew Harry Maxime A Siegler Thomas Lectka

In the realm of aliphatic fluorination, the problem of reactivity has been very successfully addressed in recent years. In contrast, the associated problem of selectivity, that is, directing fluorination to specific sites in complex molecules, remains a great, fundamental challenge. In this report, we show that the enone functional group, upon photoexcitation, provides a solution. Based solely ...

Cotton fabric was treated with fluorine gas in a nitrogen atmosphere. The effect of fluorination treatments on wettability, whiteness index, dyeability and mechanical properties of cotton fabrics were assessed. Kawabata analysis shows that fluorination treatment increases shear stiffness G, shear hysteresis 2HG5, bending stiffness B and overall fabric stiffness Koshi on cotton fabric. Fluorinat...

2017
Yang'en You Long Zhang Sanzhong Luo

A reagent-controlled enantioselectivity switch was uncovered in the asymmetric a-fluorination of bketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling modes...

Journal: :Chemical science 2017
Yang'en You Long Zhang Sanzhong Luo

A reagent-controlled enantioselectivity switch was uncovered in the asymmetric α-fluorination of β-ketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling mode...

2017
Mehrdad Balandeh Christopher Waldmann Daniela Shirazi Adrian Gomez Alejandra Rios Nathanael Allison Asad Khan Saman Sadeghi

Electrochemical fluorination of methyl(phenylthio)acetate was achieved using tetrabutylammonium fluoride (TBAF). Electrochemical fluorination was performed under potentiostatic anodic oxidation using an undivided cell in acetonitrile containing TBAF and triflic acid. The influence of several parameters including: oxidation potential, time, temperature, sonication, TBAF concentration and triflic...

2017
Buddhadev Maiti Alexander Schubert Sunandan Sarkar Srijana Bhandari Kunlun Wang Zhe Li Eitan Geva Robert J. Twieg Barry D. Dunietz

Selective fluorination of organic semiconducting molecules is proposed as a means to achieving enhanced hole mobility. Naphthalene is examined here as a root molecular system with fluorination performed at various sites. Our quantum chemical calculations show that selective fluorination can enhance attractive intermolecular interactions while reducing charge trapping. Those observations suggest...

Journal: :Science 2011
Eunsung Lee Adam S Kamlet David C Powers Constanze N Neumann Gregory B Boursalian Takeru Furuya Daniel C Choi Jacob M Hooker Tobias Ritter

The unnatural isotope fluorine-18 ((18)F) is used as a positron emitter in molecular imaging. Currently, many potentially useful (18)F-labeled probe molecules are inaccessible for imaging because no fluorination chemistry is available to make them. The 110-minute half-life of (18)F requires rapid syntheses for which [(18)F]fluoride is the preferred source of fluorine because of its practical ac...

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