- Palladium(II)-Catalyzed Oxidative Decarboxylative [2 + 2 + 1] Annulation of Cinnamic Acids with Alkynes: Access to Polysubstituted Pentafulvenes
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An unprecedented palladium(II)-catalyzed oxidative decarboxylative [2 + 2 + 1] annulation of cinnamic acids with alkynes has been developed for the synthesis of polysubstituted pentafulvenes. Ag2CO3 and DMSO are essential for the reaction. This protocol features readily available starting materials, a wide substrate scope, and moderate to excellent yields. Moreover, various significant frameworks can be easily obtained from the late-stage transformations of pentafulvenes via oxidation, reduction, and Scholl-type reaction.
- Peng, Shiyong,Chen, Nuan,Zhang, Hong,He, Min,Li, Hongguang,Lang, Ming,Wang, Jian
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supporting information
p. 5589 - 5593
(2020/07/08)
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- Method for synthesizing polysubstituted fulvene compound
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The invention discloses a method for synthesizing a polysubstituted fulvene compound. The reaction general formula of the synthesis method is as follows. According to the technical scheme, under the action of a transition metal/oxidant catalytic system, a
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Paragraph 0031-0034
(2019/11/25)
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- Palladium-catalyzed three-component 1:2:1 coupling of aryl iodides, alkynes, and alkenes to produce 1,3,5-hexatriene derivatives
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The intermolecular three-component coupling of aryl iodides, diarylacetylenes, and alkenes effectively proceeds in the presence of palladium acetylacetonate and silver acetate as catalyst and base, respectively, to give the corresponding 1:2:1 coupling pr
- Horiguchi, Hakaru,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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scheme or table
p. 1431 - 1436
(2010/02/28)
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- Palladium-catalyzed intermolecular three-component coupling of organic halides with alkynes and alkenes: Efficient synthesis of oligoene compounds
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The intermolecular three-component coupling of aryl or vinyl halides, diarylacetylenes, and monosubstituted alkenes effectively proceeds in the presence of palladium acetate, lithium chloride, and sodium bicarbonate as catalyst, promoter, and base, respectively, in aqueous DMF or DMSO to produce the corresponding 1,3-butadiene or 1,3,5-hexatriene derivatives. Use of dienyl bromides allows the coupling to afford 1,3,5,7-octatetraenes. Under the present catalytic conditions, fulvene derivatives are also formed efficiently by the 1:2 coupling of vinyl bromides and diarylacetylenes without adding the alkenes.
- Shibata, Kana,Satoh, Tetsuya,Miura, Masahiro
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p. 2317 - 2325
(2008/09/19)
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- Mizoroki-Heck type reaction of organoboron reagents with alkenes and alkynes. A Pd(II)-catalyzed pathway with Cu(OAc)2 as an oxidant
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Formula presented In contrast to the Pd(0)-catalyzed mechanism by Uemura, Mizoroki-Heck type reaction of boronic acids is found to proceed under a Pd(II)-mediated pathway using a catalytic amount of Pd(OAc)2 in the presence of Cu(OAc)2 as an oxidant. Treatment of a variety of alkenes with boronic acids, boronates, and sodium tetraphenylborate furnishes β-arylated and alkenylated products in good to excellent yields. The reactions with norbornene, norbornadiene, and diphenylacetylene are also performed to give 1:2 or 2:1 coupling products.
- Du, Xiaoli,Suguro, Masahiro,Hirabayashi, Kazunori,Mori, Atsunori,Nishikata, Takashi,Hagiwara, Nobuhito,Kawata, Kentaro,Okeda, Takeaki,Wang, Hui Feng,Fugami, Keigo,Kosugi, Masanori
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p. 3313 - 3316
(2007/10/03)
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- Low Molecular-Weight Glassy Fulvenes
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Fulvenes 3 were synthesized from 1,2,3,4-tetraphenylcyclopenta-1,3-diene (1) and different aldehydes 2. They are glass-forming materials with well-defined glass-transition temperatures between 74°C and 120°C.
- Braun,Langendorf
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- Facile synthesis of 1,2-diaryl- and triarylethenes with supported fluoride bases
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Differently substituted arenecarbaldehydes, mainly benzaldehydes, can be very efficiently condensed with a wide variety of methylbenzenes having an electron-withdrawing group in the para-position, as well as with fluorenes, xanthene, cyclopentadienes and indenes by using a standardized KF- or CsF-Al2O3 base system in dimethylformamide.
- Hellwinkel,Goke,Karle
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p. 973 - 978
(2007/10/02)
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- Palladium-catalyzed reactions of vinyl bromides with disubstituted alkynes: a new synthesis of fulvenes
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The palladium-catalyzed reaction of vinylic bromides with disubstituted acetylenes at 100 deg C in the presence of trietylamine produces penta- or hexa-substituted fulvenes in low to moderate yields.Reactions with 3-hexyne under the same conditions usually yield dialkylidenecyclopentenes as products, apparently by rearrangement of the expected fulvenes.Fulvenes formed from the reactions of disubstituted alkynes with Z-2-bromovinyl ethyl ether can be hydrolyzed to produce cyclopentadiene carboxaldehydes.
- Silverberg, Lee J.,Wu, Guangzhong,Rheingold, Arnold L.,Heck, Richard F.
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p. 411 - 420
(2007/10/02)
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- TRITOLYLARSONIUM AND TRIS(METHOXYPHENYL)ARSONIUM YLIDES THE EFFECTS OF ortho-SUBSTITUENTS IN TRIARYLARSONIUM GROUPS ON THE PROPERTIES OF YLIDES
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A number of tritolylarsonium and tris(methoxyphenyl)arsonium cyclopentadienylides and other ylides have been prepared and their properties (basicity, NMR spectra, reactions with aldehydes and nitrosobenzene, acetylation, and methanolysis) have been investigated.Substituents in the m- or p-positions of triarylarsonium groups have little effect on properties, but o-substituents result in markedly lower reactivity and lower basicity, and these ylides were also more difficult to prepare.NMR spectra gave indication of crowding in some of these o-substituted ylides.The effects of the o-substituents are discussed. p-Methyl- and p-methoxy-substituents increased the proportion of anil to ketoxime formed in reactions with nitrosobenzene, but the o-methoxy analogue gave only ketoxime.
- Harris, Gordon S.,Lloyd, Douglas,MacDonald, William A.,Gosney, Ian
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p. 297 - 304
(2007/10/02)
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