- Bis(aniline) compounds containing multiple substituents with carbon-carbon triple-bonded groups
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The invention relates to bis(aniline) compounds containing multiple arylethynyl, alkylethynyl, ethynyl groups or their combinations, processes of making such compounds and materials comprising such compounds. Such, bis(aniline) compounds preferably comprise multiple phenylethynyl (PE) groups, i.e. 2-4 PE moieties. Such compounds are useful monomers for the preparation of polyimides, polyamides and poly(amide-imides) whose post-fabrication crosslinking chemistry (i.e. reaction temperature) can be controlled by the number of PE per repeat unit as well as finding utility in thermosetting matrix resins, 3D printable resins, and as high-carbon-content precursors to carbon-carbon composites.
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Page/Page column 16
(2021/04/28)
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- Dual copper- and photoredox-catalysed C(sp2)-C(sp3) coupling
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The use of copper catalysis with visible light photoredox catalysis in a cooperative fashion has recently emerged as a versatile means of developing new C-C bond forming reactions. In this work, dual copper and photoredox catalysis is exploited to effect C(sp2)-C(sp3) cross-couplings between aryl boronic acids and benzyl bromides.
- McLean, Euan B.,Gauchot, Vincent,Brunen, Sebastian,Burns, David J.,Lee, Ai-Lan
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supporting information
p. 4238 - 4241
(2019/04/30)
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- Diarylmethanes through an Unprecedented Palladium-Catalyzed C-C Cross-Coupling of 1-(Aryl)methoxy-1 H-Benzotriazoles with Arylboronic Acids
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1-(Aryl)methoxy-1H-benzotriazoles (ArCH2OBt) are bench-stable reagents that are prepared readily from 1H-benzotriazol-1-yl-4-methylbenzenesulfonate and benzylic alcohols. These compounds, which contain a N-O-C bond, undergo cross-coupling with arylboronic acids by C-O bond scission with catalysts that comprise Pd(OAc)2 and biarylphosphine ligands. Such reactivity of ArCH2OBt derivatives, which lead to diarylmethanes, has not been described previously and constitutes a new activation of benzylic alcohols. With regard to the various ligand-metal complexes that support catalytic activity, it appears that those with smaller "percent buried volumes" (%Vbur) provide better outcomes. This factor has been evaluated in the initial optimization studies and in further reactions with difficult coupling partners. Ligand electronics of the biaryl moiety seem to play a lesser role in this type of reaction. The biscoordinating bis[(2-diphenylphosphino)phenyl] ether appears to be suitable to improve the yields of low-yielding reactions. Phosphine fine: 1-(Aryl)methoxy-1H-benzotriazoles (ArCH2OBt), which contain a N-O-C bond, undergo cross-coupling with arylboronic acids by C-O bond scission with catalysts that comprise Pd(OAc)2 and biarylphosphine ligands. Such reactivity of ArCH2OBt derivatives, which lead to diarylmethanes, has not been described previously and constitutes a new activation of benzylic alcohols.
- Singh, Manish K.,Lakshman, Mahesh K.
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p. 4156 - 4162
(2016/01/09)
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- Unusual reactivity of aryl aldehydes with triethyl phosphite and zinc bromide: A facile preparation of epoxides, benzisoxazoles, and α-hydroxy phosphonate esters
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Abstract A facile preparation of trans-epoxides was achieved by a (EtO)3P-ZnBr2-mediated deoxygenation reaction of the corresponding 2-nitrobenzaldehydes. The sterically hindered analogues of 2-nitrobenzaldehyde underwent a reaction
- Raju, Potharaju,Gobi Rajeshwaran, Ganesan,Nandakumar, Meganathan,Mohanakrishnan, Arasambattu K.
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p. 3513 - 3523
(2015/06/08)
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- Substituted diaryldiazomethanes and diazofluorenes: Structure, reactivity and stability
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The synthesis of several substituted diaryldiazomethanes and diazofluorenes, and an assessment of their structure, reactivity and stability, is reported.
- Davis, Philip J.,Harris, Lawrence,Karim, Aman,Thompson, Amber L.,Gilpin, Martin,Moloney, Mark G.,Pound, Matthew J.,Thompson, Claire
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supporting information; experimental part
p. 1553 - 1556
(2011/04/26)
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- The formation of 4,4′-difluorobenzophenone from 4,4′-dinitrodiphenylmethane
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The novel one pot oxidation/fluorodenitration of 4,4′-dinitrodiphenylmethane to form 4,4′-difluorobenzophenone has been achieved using tetramethylammonium fluoride in N,N-dimethylacetamide.
- Adams, Dave J.,Clark, James H.,McFarland, Heather
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p. 127 - 129
(2007/10/03)
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- A Variant of Peterson Olefination: Nitrophenyl-Substituted Methylenecyclopropanaphthalenes
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The successful use of a gem-disilyl compound in Peterson olefination with nitrosubstituted aromatic aldehydes and ketones is achieved for 1,1-bis(trimethylsilyl)-1H-cyclopropanaphthalene (9) by employing potassium fluoride in acetonitrile and using a c
- Halton, Brian,Lu, Qi,Stang, Peter J.
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p. 1277 - 1282
(2007/10/02)
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- Solvent Dependence of the Ionization of Nitrophenylmethanes
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The solvent dependence of proton abstraction from various nitrophenylmethanes has been examined for aqueous dimethyl sulphoxide and methanolic dimethyl sulphoxide solutions.Even though the compounds studied vary considerably in thermodynamic acidity (pKa), their proton-abstraction rates all show the same solvent dependence.It is suggested that the transition states for these reactions all occur at similar positions on the reaction pathway, and that transition state imbalances exist for these proton transfers.
- Fogel, Paula,Farrel, Patrick G.,Lelievre, Jacques,Chatrousse, Alain P.,Terrier, Francois
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p. 711 - 716
(2007/10/02)
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