2294-87-3Relevant academic research and scientific papers
Synthesis and characterization of 1- and 2-(ω-alken-1-yl)indenes, their lithium salts and dichlorozirconium(IV) complexes
Schumann, Herbert,Karasiak, Dirk F.,Muehle, Stefan H.,Halterman, Ronald L.,Kaminsky, Walter,Weingarten, Ulrich
, p. 356 - 372 (1999)
A series of new 1-, 2-, and multi-substituted indenes has been synthesized and characterized. The reaction of indenyl lithium or 4,7-dimethylindenyl lithium with alkenyl bromides yielded a mixture of 1- and 3-allylindene (1), 3-(3-buten-1-yl)indene (2), 3-(4-penten-1-yl)indene (3), 3-allyl-4,7-dimethylindene (4), 3-(3-buten-1-yl)-4,7-dimethylindene (5), as well as 3-(4-penten-1-yl)-4,7-dimethylindene (6). The 2-substituted indenes 2-allylindene (7), 2-(3-buten-1-yl)indene (8), 2-(4-penten-1-yl)indene (9), 2-allyl-4,7-dimethylindene (10), 2-(3-buten-1-yl)-4,7-dimethylindene (11), and 2-(4-penten-1-yl)-4,7-dimethylindene (12) were prepared by PdCl2(DPPF) or NiCl2(DPPE) catalyzed cross-coupling reactions of the appropriate Grignard reagents with 2-bromoindene or 2-bromo-4,7-dimethylindene. Alkenylation of 3-methylindenyl lithium and 2,4,7-trimethylindenyl lithium produced 1-(3-buten-1-yl)-3-methylindene (13) or 1-(3-buten-1-yl)-2,4,7-trimethylindene (14), respectively. The indene derivatives 1-14 react with n-butyl lithium in hexane yielding the corresponding lithium salts 1a-14a. Zirconium tetrachloride reacts with 1a, 2a, 4a-6a and 11a-14a under formation of the corresponding bis(indenyl)zirconium dichloride complexes 1b, 2b, 4b-6b and 11b-14b. All compounds were characterized by elemental analysis, 1H and 13C{1H}-NMR spectroscopy and mass spectrometry, 5b and 12b also by single crystal X-ray structural analysis. 1b, 4b-6b and 11b-13b are active catalysts for the polymerization of ethene and propene.
Gold- or Indium-Catalyzed Cross-Coupling of Bromoalkynes with Allylsilanes through a Concealed Rearrangement
De Orbe, M. Elena,Zanini, Margherita,Quinonero, Ophélie,Echavarren, Antonio M.
, p. 7817 - 7822 (2019/08/20)
The gold(I)-catalyzed reaction of bromoalkynes with allylsilanes gives 1,4-enynes in a formal cross-coupling reaction. Mechanistic studies revealed the involvement of gold(I) vinylidenes or vinylidenephenonium gold(I) cations depending on the substituent on the bromoalkyne. In the case of bromo arylalkynes, the vinylidenephenonium gold(I) cations lead to 1,4-enynes via a 1,2-aryl rearrangement. The same reactivity has been observed in the presence of InBr3
HIGH ACTIVITY CATALYST COMPOSITIONS CONTAINING SILICON-BRIDGED METALLOCENES WITH BULKY SUBSTITUENTS
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Page/Page column 59, (2013/03/26)
The present invention discloses catalyst compositions employing silicon-bridged metallocene compounds with bulky substituents. Methods for making these silicon-bridged metallocene compounds and for using such compounds in catalyst compositions for the polymerization of olefins also are provided.
Towards benign synthesis of indenes from indanones: Zinc-mediated allylation of ketones in aqueous media as a source of substituted indenyl ligand precursors
Silver, Satu,Leppaenen, Ann-Sofie,Sjoeholm, Rainer,Penninkangas, Antti,Leino, Reko
, p. 1058 - 1081 (2007/10/03)
Substituted indenes are valuable ligand precursors for transition-metal complexes. Previously, most of the methods employed for the preparation of alkyl-substituted indenes have involved the use of air-sensitive organometallic lithium or Grignard reagents
Nickel-Catalyzed Olefination of Cyclic Benzylic Dithioacetals by Grignard Reagents. Scope and Mechanism
Ni, Zhi-Jie,Mei, Nai-Wen,Shi, Xian,Tzeng, Yih-Ling,Wang, Maw Cherng,Luh, Tien-Yau
, p. 4035 - 4042 (2007/10/02)
The details of the first nickel-catalyzed olefination of cyclic dithioacetals to form substituted styrenes and aryl-substituted 1,4-pentadienes are described.The reaction represents a new synthetic use of the dithioacetal functionality.Only nickel complexes catalyzes these cross-coupling reactions; palladium complexes displayed no catalytic activity under the reaction conditions employed.Selective coupling occurred.A mechanism for the reaction is proposed.The experimental evidence indicates that, in these nickel-catalyzed couplings, cyclic dithioacetals are more reactive than their acyclic analogues.This increased reactivity appears to be the result of maintaining the two sulfur atoms in close proximity to each other by the use of a short chain of methylene groups.
Synthesis of the Benzotricyclooctane Ring System. Intramolecular Cycloaddition of Indene Derivatives
Padwa, Albert,Goldstein, Steven,Pulwer, Mitchell
, p. 3893 - 3902 (2007/10/02)
The photosensitized triplet reactions of several 1-allyl-substituted indenes have been studied.The triplet-sensitized irradiations gave benzotricyclo2,7>octanes in good yield by means of a novel intramolecular cycloaddition.The effect of substituents on the regioselectivity of the sensitized rearrangement was studied in some detail.With the simple 1-allyl-substituted isomer, 1,5-cyclization of the excited state is the preferred path.This mode of cyclization is favored on the basis of strain, radical stability, and entropy factors.We have found, however, that the normal closure predicted by the rule of five does not occur in the photosensitized irradiation of the 1-prenyl-substituted isomer.With this system, intramolecular cycloaddition gives rise to the benzotricyclooctane system.The diradical produced from the sensitized 1,4-cyclization path is long lived enough to allow internal disproportionation to complete with radical coupling.The facility with which the intramolecular indene photocycloadditions occur makes this type of approach particularly attractive for the synthesis of some unusual polycyclic ring compounds.
