94445-40-6Relevant academic research and scientific papers
Ethylene-bridged C1-symmetric ansa-(3-R-indenyl)(fluorenyl) zirconocene complexes for propylene dimerization or polymerization: The effect of R group
Wang, Yan,Huang, Wenzhong,Ma, Haiyan,Huang, Jiling
, p. 81 - 93 (2014/05/06)
A series of ethylene-bridged C1-symmetric ansa-(3-R-indenyl) (fluorenyl) zirconocene complexes 3a-i (R = 2-[2-(4-methylphenyl)propyl], 3a; R = 2-[2-(3,5-dimethylphenyl)propyl], 3b; R = 2-(2-benzylpropyl), 3c; R = 2-methylbenzyl, 3d; R = 2-(2-cyclohexylpropyl), 3e; R = 2-[2-(1-cyclohexenyl) propyl], 3f; R = 2-(2-n-butylpropyl), 3g; R = cyclohexyl, 3h; R = iPr, 3i) were synthesized by a salt metathesis method and characterized by NMR spectroscopy, elemental analysis (or HRMS) and X-ray diffraction (3e and 3h). Upon activation with methylaluminoxane, most of these zirconocene complexes exhibited sufficient catalytic activities up to 2.5 × 105 g C6/(mol-Zr·h) and high selectivities up to 99% toward propylene dimerization, affording 2-methyl-1-pentene as the major isomer which was confirmed by gas chromatography. Remarkably, the selectivity and activity of complexes 3a-i were significantly influenced by the structural features of the substituent on the 3-position of indenyl ring: a pendant aryl or alkyl group linked by a quaternary carbon bridge provided the complex with high selectivities in the range of 89.9-99.0% for 2-methyl-1-pentene and low to moderate catalytic activities; the lack of a quaternary carbon bridge within the substituent would lead to mainly polypropylenes of low molecular weight. The steric hindrance around the active metal center induced by the pendant group might be responsible for the catalytic dimerization behavior, and the presumed mechanism was discussed. In addition, for complexes 3h and 3i, the selectivity for propylene dimerization could also be enhanced with the increase of reaction temperature. Noticeably, most of these ansa-zirconocene complexes exhibit excellent thermal stability at 100 °C, which is important with regard to industrial application. 2014 Elsevier Ltd. All rights reserved.
1,2,3-trisubstituted indanes by highly diastereoselective palladium-catalyzed oxyarylation of indenes with arylboronic acids and nitroxides
Kirchberg, Sylvia,Froehlich, Roland,Studer, Armido
supporting information; experimental part, p. 6877 - 6880 (2010/12/19)
Chemecal quation presented Excellent stereoselectivity is obtained in the synthesis of biologically interesting 1,2,3-trisubstituted indanes B by the reaction of readily prepared 3-substituted indenes A with commercially available arylboronic acids by using various TEMPO derivatives as external oxidants and Pd(OAc)2 as a catalyst. The anti,anti isomers are formed and reactions occur stereospecifically under mild conditions.
Silver-catalyzed coupling reactions of alkyl halides with indenyllithiums
Someya, Hidenori,Yorimitsu, Hideki,Oshima, Koichiro
experimental part, p. 5993 - 5999 (2010/09/10)
Coupling reactions of tertiary and secondary alkyl halides with indenyllithiums proceeded effectively in the presence of a catalytic amount of silver bromide to provide tertiary- and secondary-alkyl-substituted indene derivatives in good yields.
Dipolar cycloaddition reactions of diazoindene and the thermal behavior of the cycloadducts
Padwa, Albert,Goldstein, Steven I.
, p. 2506 - 2514 (2007/10/02)
A study of the dipolar cycloaddition behavior of diazoindene toward electron-deficient acetylenic and olefinic dipolarophiles has been carried out.Reactions with alkynes afford transient 1,3-dipolar cycloadducts.Product formation can be attributed to a substituent-dependent partioning between spiro 3H-pyrazole adducts and ring opened diazoalkenes.The initially formed cycloadducts lose nitrogen to give a spirocyclopropene derivative or undergo the van Alpen - Huttel rearrangement.When olefinic dipolarophiles are used, nitrogen deficient 1:1 adducts are isolated.The formation of the product involves the further loss of nitrogen from the initially formed spiropyrazoline adduct.
