- Selective Functionalization in the Bay Region of Polycyclic Aromatic Hydrocarbons via Dilithiation
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Sequential reaction of policyclic aromatic hydrocarbons with butyllithium/TMEDA hexane and electrophiles allows preparation of derivatives functionalized in the bay region.
- Ashe, Arther J.,Kampf, Jeff W.,Salva, Paresh M.
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- Photodeoxygenation of phenanthro[4,5-bcd]thiophene S-oxide, triphenyleno[1,12-bcd]thiophene S-oxide and perylo[1,12-bcd]thiophene S-oxide
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Sulfoxides, upon irradiation with ultraviolet (UV) light undergo α-cleavage, hydrogen abstraction, photodeoxygenation, bimolecular photoreduction, and stereo-mutation. The UV irradiation of dibenzothiophene S-oxide (DBTO) yields dibenzothiophene (DBT) as a major product along with ground-state atomic oxygen [O(3P)]. This is a common method for generating O(3P) in solution. The low quantum yield of photodeoxygenation and the requirement of UVA light are drawbacks of using this method. The sulfoxides benzo[b]naphtho-[1,2,d]thiophene S-oxide, benzo[b]naphtho [2,1,d]thiophene S-oxide, benzo[b] phenanthro[9,10-d]thiophene S-oxide, dinaphtho- [2,1-b:1’,2’-d]thiophene S-oxide, and dinaphtho[1,2-b:2’,1’-d]thiophene S-oxide have shown to deoxygenate up to three times faster than DBTO upon UVA irradiation; however, the photodeoxygenation of these sulfoxides does not appear to be limited to the production of O(3P). In this work, phenanthro[4,5-bcd]thiophene S-oxide, triphenyleno[1,12-bcd]thiophene-S-oxide, and perylo[1,12-bcd]thiophene-S-oxide were synthesized and their photodeoxygenation was studied. Phenanthro[4,5-bcd]thiophene-S-oxide, triphenyleno[1,12-bcd]thiophene-S-oxide, and perylo[1,12-bcd]thiophene-S-oxide deoxygenated upon UVA irradiation. However, the common intermediate experiments did not conclusively identify the photodeoxygenation mechanism of these sulfoxides.
- Chintala, Satyanarayana M.,Petroff II, John T.,Barnes, Andrew,McCulla, Ryan D.
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p. 503 - 515
(2019/05/29)
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- Triphenylene-Benzofuran/Benzothiophene/Benzoselenophene Compounds With Substituents Joining To Form Fused Rings
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Compounds comprising a triphenylene moiety and a benzo- or dibenzo-moiety are provided. In particular, the benzo- or dibenzo-moiety has a fused substituent. These compounds may be used in organic light emitting devices, particularly in combination with yellow, orange and red emitters, to provide devices with improved properties.
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- The Insertion and Extrusion of Heterosulfur Bridges. XV. S-Bridging of 2,2'-Binaphthyl and 1-(2-Naphthyl)cyclohexene. Studies on Hydrodehalogenation During the Reaction
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Regioselectivity occurs in the sulfur-bridging reactions of 2,2'-binaphthyl (1) and 1-(2-naphthyl)cyclohexene (7) by means of hydrogen sulfide and a chromia-alumina-magnesia catalyst (designated I) in a flow apparatus at 550 deg C.Thus, 1 gives a higher yield (6.1percent of dinaphthothiophene from 1,1'-bridging than of dinaphthothiophene (3.4percent) from 1,3'-bridging.No product expected from 3,3'-bridging was identified.Substrate 7 undergoes both dehydrogenation and bridging to yield 2-phenylnaphthalene (8percent), benzonaphthothiophene (9percent) from alpha briding, and benzonaphthothiophene (3percent) from beta bridging into the naphthalene ring.Exploratory studies showed that either sulfided catalyst I or a sulfided molybdenum(VI) oxide-alumina-cobalt(II) oxide catalyst (II) effects hydrodehalogenation of various monohalo- and polyhaloarenes (where halo, X, is chloro or bromo) at 450-550 deg C.In the biphenyl, phenanthrene, naphthalene, and pyrene systems, halogen was lost either under sulfur-bridging conditions or under hydrogenolysis conditions, i.e. with methanol as a reactant.For every substrate the parent arene was isolated or identified as a reaction product.In selected experiments, acid HX was also identified in the effluent.Use of hydrogen sulfide as a reactant led to formation of dibenzothiophene and phenanthrothiophene as main products in the biphenyl and phenanthrene systems, respectively; while use of methanol as a reactant gave small amounts of methyl bromide (for X = Br) and methylarenes.
- Klemm, L. H.,Stevens, Michael P.,Tran, Long K.,Sheley, John
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p. 1111 - 1116
(2007/10/02)
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- The Insertion and Extrusion of Heterosulfur Bridges. XIII. Syntheses and Structural Studies of Nitrophenanthrothiophenes
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A simplified procedure for sulfur bridging of phenanthrene (2a) with hydrogen sulfide and a catalyst, but without solvent, is described.The product, phenenthrothiophene (1a), undergoes nitration at 25 deg C or 60 deg C in acetic anhydride to give mixtures (56-79percent) of 1-nitro-1a and 3-nitro-1a in varying ratios.Reductive acetylation of these nitro derivatives gives 1- and 3-acetylamino-1a (93percent and 33percent).Hydrodesulfurization of the former amide produces crude 1-acetylamino-2a.Positions of substitution are assigned primarily on the basis of nmr chemical shifts of protons ortho or peri to the nitro substituent, and are consistent with calculations of reactivity indices by simple Hueckel molecular orbital theory.
- Klemm, L. H.,Tsuchiya, Reiko,Wong, Eric K. L.,Stevens, Michael P.,Lu, Jennifer J.,Klopfenstein, C. E.
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p. 357 - 360
(2007/10/02)
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- The Insertion and Extrusion of Heterosulfur Bridges. XII. Selectivity and Side Reactions in the Bridging Process
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1-Phenylnaphthalene undergoes sulfur bridging at 500 deg C in the presence of hydrogen sulfide and a heterogeneous catalyst to produce benzonaphthtothiophene (13percent). 3-Methylphenanthrene and 9-formylphenanthrene diethyl acetal (7b) give sulfur bridging to produce phenanthrothiophene, i.e. with loss of the ring substituent.Additionally, 7b hydrogenolyses to 9-methylphenanthrene.With decadeuteriobiphenyl as a substrate, the dibenzothiophhene formed, as well as biphenyl recovered, is largely devoid of deuterium label.Confirmation that benzene and toluene react under sulfur-bridging conditions is presented.
- Klemm, L. H.,Pou, Sovitj,Detlefsen, W. D.,Higgins, Clay,Lawrence, Ross F.
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p. 1293 - 1296
(2007/10/02)
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- The Synthesis of Phenanthrothiophene and Four Monomethylphenanthrothiophenes
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The synthesis of phenanthrothiophene and four monomethylphenanthrothiophenes is described.
- Tedjamulia, Marvin L.,Tominaga, Yoshinori,Castle, Raymond N.,Lee, Milton L.
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p. 1149 - 1152
(2007/10/02)
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