- ORTHO-SUBSTITUTED TRIPTYCENE-BASED DIAMINES, MONOMERS, AND POLYMERS, METHODS OF MAKING AND USES THEREOF
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Described herein are ortho-dimethyl-substituted and tetramethyi-substituted triptycene-containing diamine monomers and microporous triptycene-based poiyimides and poiyamides, and methods of making the monomers and polymers.
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Paragraph 0049
(2019/03/08)
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- Versatile synthesis of triptycene di- and tetracarboxylic acids
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A simple two-step synthesis of triptycene di- and tetracarboxylic acids is reported. Diels-Alder reaction between dimethylanthracenes and appropriate arynes, generated in situ from anthranilic or dimethylanthranilic acid, afforded di- or tetramethyltriptycenes in 41-69% yields. Subsequent oxidation of the methyl groups with potassium permanganate provided the corresponding triptycene carboxylic acids in 86-96% yields. Georg Thieme Verlag Stuttgart.
- Rybackova, Marketa,Belohradsky, Martin,Holy, Petr,Pohl, Radek,Zavada, Jiri
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p. 2039 - 2042
(2007/10/03)
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- Two-photon absorption properties of 2,6-bis(styryl)anthracene derivatives: Effects of donor-acceptor substituents and the π center
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A series of 2,6- and 2,7-bis-(styryl)anthracene derivatives with the donors at the styryl group and acceptors at the 9,10-positions have been synthesized, and their two-photon cross sections (φδmax) were determined. These compounds exhibit a peak two-photon absorptivity (δmax) in the range of 700-2500 GM at 780-1030 nm. Values of λmax and Stokes shifts increase as the acceptor is changed to a stronger one. There is also a parallel increase in λmax (2) and δmax with the same variation of the chromophore structure. Both λmax(2) and φδmax have been optimized by introducing donor-substituted styryl groups at the 2,6-positions and p-cyanophenyl groups at the 9,10-positions, respectively. The effect of a π center on the two-photon absorption properties has been assessed by comparing the existing data for a variety of D-π-D derivatives.
- Yang, Wen Jun,Kim, Dae Young,Jeong, Mi-Yun,Kim, Hwan Myung,Lee, Yun Kyoung,Fang, Xingzhong,Jeon, Seung-Joon,Cho, Bong Rae
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p. 4191 - 4198
(2007/10/03)
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- Friedel-Crafts Reaction with Arylcarbinols : One-Pot Synthesis of 10-Methylbenzo[a]fluoranthene
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Friedel-Crafts reaction with some monoaryl and diaryl carbinols have been studied. The products suggest a rational mode of formation of trityl alcohol and anthracene derivatives modifying the earlier reported conjecture of their formation from carbon monoxide, generated from benzhydrol and solvent benzene. It now appears that during Friedel-Crafts reaction the benzyl carbocation generated from benzhydrol may be arylated to triphenylmethane derivative. The latter under the experimental condition forms trityl cation which abstracts the hydroxyl group from the benzhydrol to form benzyl carbocation and trityl alcohol. Benzyl carbocations act both as a nucleophile and an eletrophile and dimerize to form anthracene derivatives. Incidentally, a one-pot synthesis of 10-methylbenzo[a]fluoranthene (26), characterized by NOE, decoupling and mass spectral studies, has been achieved in good yield by the Friedel-Crafts reaction of 9-fluourenol, thus providing a simple method of its synthesis.
- Talapatra, Bani,Chakraborty, Syamal,Biswas, Kallolmay,Mondal, Sudipta,Talapatra, Sunil Kumar
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p. 788 - 794
(2007/10/03)
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- Dealkylation of tert-butylcalix[n]arenes in toluene: Formation of 2,6 and 2,7-dimethylanthracenes
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An eutectic mixture of 2.6-dimethylanthracene VI and 2,7-dimethylantracene VII was formed during deterbutylation reaction of calix[n]arenes in toluene with aluminium chloride as catalyst. Using the deterbutylation of p-tert- butylcalix |4]arene I as a model we propose a mechanism of their formation. Springen Verlag Iberica 1997.
- Yao, Benjamin,Bassus, Jacques,Lamartine, Roger
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p. 165 - 167
(2007/10/03)
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- An Efficient Reduction of Anthrones to Anthracenes
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An efficient and general means of reducing anthrones to anthracenes has been developed.The procedure, which uses NaBH4 as the reducing agent in a mixed solvent system of diglyme/methanol, produced anthracenes in essentially quantitative yield from a variety of anthrones.
- Marquardt, Donald J.,McCormick, Frankie A.
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p. 1131 - 1134
(2007/10/02)
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- Unsymmetrically substituted 2,7-dimethyl-1,8-diarylanthracenes
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A synthesis has been developed for 2,7-dimethyl-1,8-di-o-tolylanthracene 4. The cis 4a and trans 4b isomers of this hydrocarbon can be separated and are stable to interconversion at temperatures below 200 °C. The two enantiomers of the trans isomer 4b have chiral cavities and are expected to be useful precursors for chiral reagents or chiral catalysts.
- House,Holt,VanDerveer
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p. 7516 - 7523
(2007/10/02)
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- Synthesis of 2,7-Dimethylanthracene by a Route Which is Potentially a General One
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A synthetic route to specifically substituted anthracenes was attempted by using a selectively substituted o-bromobenzaldehyde derivative as the precursor. 2,7-Dimethylanthracene was successfully prepared.H 9 and H 10 in 2,7-dimethylanthracene were readily assigned by n.O.e. experiments.
- Lai, Yee-Hing,Peck, Thian-Guan
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p. 2067 - 2071
(2007/10/02)
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- The Question of Friedel-Crafts Transformylations. Acid-Catalyzed Reactions of Aromatic Aldehydes with Arenes
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The reactions of aromatic aldehydes with various arenes in the presence of Lewis and Broensted acids have been examined with the aim of determining if transformylations occur.No evidence for such transformylations was obtained.The major initial reaction is nucleophilic addition of the arene to the carbonyl group of the aldehyde to produce a diarylmethanol, followed by reaction with a second molecule of arene with elimination of water to produce a triarylmethane.Further reactions include (1) reversible dealkylations/realkylations of triarylmethanes to yield di- and triarylmethanes having aromatic nuclei corresponding to those of both the initial aldehyde and the arene and (2) alkylation, cyclialkylation, and dealkylation reactions that result in the formation of anthracene and/or substituted anthracenes and dihydroanthracenes.The anthracene and dihydroanthracene derivatives are produced in significant amounts only when aluminum chloride is the acid catalyst.The mechanisms of the reactions of aromatic aldehydes with arenes in the presence of aluminum chloride are discussed and compared with reactions of aromatic ketones.
- Roberts, Royston M.,El-Khawaga, Ahmed M.,Sweeney, Kevin M.,El-Zohry, Maher F.
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p. 1591 - 1599
(2007/10/02)
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- Cycloarenes, a New Class of Aromatic Compounds, IV. - Attempts to Synthesize Cyclononakisbenzene and Cyclodecakisbenzene
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With the aim to synthesize 3 the dithiaphane 5 was prepared from which via 6 the anthracenobenzophenanthrenophane 10 was obtained.The corresponding phane-diene 11 was prepared from 5 via 12 and 13.The conformations of 5, 10, and 11 are discussed on the basis of 1H NMR spectra. - Nonoxidative photocyclisation of 11 yielded 14 which was dehydrogenated to yield the new aromatic system 15.The second internal ring closure to 3 so far did not succeed. - As precursors for the synthesis of 4 the dibenzoanthracenophenanthrenophanes 19 and 20 as well as the corresponding phane-dienes 23 and 24 were prepared via 18.Attempts to cyclodehydrogenate to 4 failed.In this context the conformations of 19, 20, 23, and 24 are discussed based on 1H NMR spectra.
- Staab, Heinz A.,Sauer, Manfred
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p. 742 - 760
(2007/10/02)
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