Trifluoromethoxy benzene in the gas phase studied by electron diffraction and spectroscopy supplemented with ab initio calculations

Shishkov, Igor F.; Geise, H. J.; Alsenoy, C. Van; Khristenko, L. V.; Vilkov, L. V.; Senyavian, V.M.; Veken, B. Van der; Herrebout, Wouter A.; Lokshin, B. V.; Garkusha, O. G.

doi:10.1016/s0022-2860(01)00564-6

Cited by 41 publications

(34 citation statements)

References 21 publications

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“…Polymer 2c was found to have a lower glass transition temperature of 29 °C relative to that of 2b . The lower glass transition temperature for the former material might be explained by the smaller barrier of rotation for the protruding (trifluoromethoxy)ether group which has the effect of introducing chain flexibility and additional free volume . The T g of 2d (52 °C), higher than 2b (38 °C), is consistent with the trend detected when comparing the organic polymers polystyrene (105 °C) and poly(2,5‐bis(trifluoromethyl)styrene) (116 °C) .…”

Section: Resultssupporting

confidence: 78%

Synthesis, Characterization, and Properties of Poly(aryl)phosphinoboranes Formed via Iron‐Catalyzed Dehydropolymerization

Turner

Resendiz-Lara

Jurca

et al. 2017

Macro Chemistry & Physics

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The dehydropolymerization of the primary phosphine–boranes, RPH2•BH3 (1a–f) (R = 3,4‐(OCH2O)C6H3 (a), Ph (b), p‐(CF3O)C6H4 (c), 3,5‐(CF3)2C6H3 (d), 2,4,6‐(CH3)3C6H2 (e), 2,4,6‐tBu3C6H2 (f)) is explored using the precatalyst [CpFe(CO)2OTf] (I) (OTf = OS(O)2CF3), based on the earth abundant element Fe. Formation of polyphosphinoboranes [RPH‐BH2]n (2a–e) is confirmed by multinuclear NMR spectroscopy, but no conversion of 1f to 2f is detected. Analysis by electrospray ionization mass spectrometry confirms the presence of the anticipated polymer repeat units for 2a–e. Gel permeation chromatography (GPC) confirms the polymeric nature of 2a–e and indicates number‐average molecular weights (Mn) of 12 000–209 000 Da and polydispersity indices between 1.14 and 2.17. By contrast, thermal dehydropolymerization of 1a–e in the absence of added precatalyst leads to formation of oligomeric material. Interestingly, polyphosphinoboranes 2c and 2d display GPC behavior typical of polyelectrolytes, with a hydrodynamic radius dependent on concentration. The thermal transition behavior, thermal stability, and surface properties of thin films are also studied.

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Section: Resultssupporting

confidence: 78%

Synthesis, Characterization, and Properties of Poly(aryl)phosphinoboranes Formed via Iron‐Catalyzed Dehydropolymerization

Turner

Resendiz-Lara

Jurca

et al. 2017

Macro Chemistry & Physics

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“…1a), which prevents the free rotation of the adjacent amide or carbamate group (see ESI † ). 7,42–45 Finally, the regioselectivity erodes as the reaction temperature increases ( 2d – f , 2o , 2u ).…”

Section: Resultsmentioning

confidence: 99%

Access to a new class of synthetic building blocks via trifluoromethoxylation of pyridines and pyrimidines

Feng

Lee

et al. 2016

Chem. Sci.

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Since the first synthesis of trifluoromethyl ethers in 1935, the trifluoromethoxy (OCF3) group has made a remarkable impact in medicinal, agrochemical, and materials science research. However, our inability to facilely incorporate the OCF3 group into molecules, especially heteroaromatics, has limited its potential across a broad spectrum of technological applications. Herein, we report a scalable and operationally simple protocol for regioselective trifluoromethoxylation of a wide range of functionalized pyridines and pyrimidines under mild reaction conditions. The trifluoromethoxylated products are useful scaffolds that can be further elaborated by amidation and palladium-catalysed cross coupling reactions. Mechanistic studies suggest that a radical O-trifluoromethylation followed by the OCF3-migration reaction pathway is operable. Given the unique properties of the OCF3 group and the ubiquity of pyridine and pyrimidine in biologically active molecules and functional materials, trifluoromethoxylated pyridines and pyrimidines could serve as valuable building blocks for the discovery and development of new drugs, agrochemicals, and materials.

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“…Fluorination of the methyl group has a strong effect on the conformation of anisole. In trifluoromethoxybenzene (a,a,a-trifluoroanisole) [9,10] and in p-fluoro(trifluoromethoxy)benzene (4,a,a,a-tetrafluoroanisole) [11] the CF 3 group is oriented perpendicular to the plane of the benzene ring (t(C2C1-OC) = 908). A small contribution of a planar conformer cannot definitely be excluded.…”

Section: Introductionmentioning

confidence: 99%

Effect of fluorination: Conformation of 2,6-difluoroanisole

Zarembo

Belyakov

Trautner

et al. 2006

Journal of Fluorine Chemistry

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Trifluoromethoxy benzene in the gas phase studied by electron diffraction and spectroscopy supplemented with ab initio calculations

Cited by 41 publications

References 21 publications

Synthesis, Characterization, and Properties of Poly(aryl)phosphinoboranes Formed via Iron‐Catalyzed Dehydropolymerization

Synthesis, Characterization, and Properties of Poly(aryl)phosphinoboranes Formed via Iron‐Catalyzed Dehydropolymerization

Access to a new class of synthetic building blocks via trifluoromethoxylation of pyridines and pyrimidines

Effect of fluorination: Conformation of 2,6-difluoroanisole

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