1064-37-5Relevant academic research and scientific papers
A variation of titanium-induced carbonyl coupling - Synthesis and conformations of terfluorenyl
Pogodin, Sergey,Cohen, Shmuel,Agranat, Israel
, p. 1979 - 1984 (1999)
Reaction of fluorenone (4) with a low-valent titanium reagent generated from TiCl4 and Zn in THF in the presence of pyridine gave terfluorenyl (6) in 71% yield, bifluorenylidene (2), the conventional McMurry reaction product, in 2% yield, and additional reduction products. The reductive 'trimerization' was rationalized in terms of an attack of the intermediate fluorenone dianion on bifluorenylidene. The molecular structure of a single crystal of 6 indicated an approximately C2 conformation, with a slightly twisted central ring, and two equally folded side moieties with dihedral angles of 58.1°and 58.0°between the central and side five-membered rings. The AM1 and PM3 calculations showed C2 global minima, similar to the conformation in the crystal. The calculated C(s) transition state conformations were found to be 21.3 (AM1) and 19.9 (PM3) kcal/mol higher in energy than the global C2 minima. A 2D-NMR NOESY experiment on 6 supported the C2 (+sc,+sc) or C2 (-sc,-sc) conformation in solution.
Novel synthetic approach in microwave-assisted solid-supported oxidations using 'in situ' generated molecular oxygen
Gershonov, Eytan,Katz, Esther,Karton, Yishai,Zafrani, Yossi
, p. 3762 - 3767 (2008/02/01)
Three different types of oxidation reactions were carried out under microwave (MW) conditions in dry media, with nearly quantitative yield, using 'in situ', yet separately generated molecular oxygen as the reactive gas. The latter is formed by a controlled decomposition of potassium chlorate (220-306 °C) adsorbed on zeolite support, and is used as a reactive oxidizing agent for the solid-supported oxidations. The MW-assisted oxidations include an oxidative decomplexation of (η6-arene)Cr(CO)3 complexes to the corresponding arenes using silica as solid support (100 °C), an oxidation of fluorene to fluorenone induced by KF-alumina support (150 °C), and oxidation of benzyl alcohol to benzaldehyde using a supported ruthenium catalyst (150 °C). This synthetic approach allows to carry out in synchronized manner two different solid-supported reactions (oxygen generation and oxidation) at different temperatures and on different solid supports together in the same sealed system. It was made possible by tuning the absorption efficiency of MWs through accurate selection of the solid supports employed in the reactions. The high feasibility of this novel synthetic approach resulted from a preliminary study of the interaction between MWs and mineral oxides such as alumina, silica, clay, and zeolite particularly when mixed with additives such as water, ionic liquids or graphite (5% w/w). The use of these MW absorber additives allows the MW transparent or poorly absorbing mineral oxides to be efficiently heated to very high temperatures in few minutes.
Extremely Reactive C=C Double Bonds, VI. - Tris(methylphenylamino)methane - The Chemistry of Orthoamides
Schoenberg, Alexander,Singer, Erich,Stephan, Werner
, p. 1581 - 1588 (2007/10/02)
Reactions of the title compound 2 with sulfur, selenium, thiophenol, malononitrile, 1,3-indanedione, fluorenone hydrazone, phenylmagnesium bromide, bromine, thioacetic acid, N,N'-diphenylurea, oxalyl chloride, 9,9-dichloroxanthene, phenyl isocyanate, and stilbene dibromide are described and the mechanisms are discussed.The catalytic influence of 2 on the decomposition of 9-diazofluorene in xylene and mesitylene is discussed.
Synthesis of gem-9,9-Dilithiofluorene by Thermal Rearrangement
Chauhan, Harendra P.S.,Kawa, Hajimu,Lagow, Richard J.
, p. 1632 - 1633 (2007/10/02)
The synthesis of an aromatic gem-dilithiumsubstituted fluorene by thermal rearrangement is described.
