Fluorene synthesis

MASCARELLI Fluorene Synthesis Synthesis of fluorenes from 2-amino-2 -alkylbiphenyls via diazonium ions (see 1st edition). 

H-2, 2 -Spirodibenzo-1,3,2-dioxaphosphole synthesis, 1, 522 Spiro[fluorene-9,3 -indazole] photolysis, 5, 252... 

Recently, polyimines include the synthesis of long alkoxy (Cg-Cig) side chain derivatives [188,189], which are presumably soluble to some extent in organic solvents and derivatives containing fluorene cardo unit [190]. Trifluoromethyl groups [191] in the polymer backbone provide solubility in organic solvents. Studies of the electrical conductivity of doped conjugated aromatic polyimines and alkoxy derivatives have been reported [188], and the values are in the range of 10 to 10 S/ cm. 

One of the first examples was the above mentioned work from Yoshino et al. [7] concerning the synthesis of poly(9,9-dialkylfluorene)s via oxidative coupling of fluorene derivatives. Poly(9,9-dialkylfluorene) derivatives have been also synthesized via Ni- and Pd-catalyzed aryl-aryl homo- and cross-coupling reactions of sui-... 

Intramolecular arylations can also be carried out photochemically. Huisgen and Zahler (1963 a) prepared fluoren-9-one by irradiation of benzophenone-diazonium salts in dilute sulfuric acid. The classical Pschorr synthesis of phenanthrene-9-carb-... 

One of the first examples was that reported by Yoshino et al. [12] concerning the synthesis of polyfluorenes via oxidative coupling of fluorene derivatives as decribed above. 

Henkel B, Bayer E. 9-Hydroxy-9-(4-carboxyphenyl)fluorene—a new linker for solid phase synthesis. Tetrahedron Lett 1998 39 9401-9402. 

Selective transformations Selective styrene ring opening [103] One-pot domino process for regioselective synthesis of a-carbonyl furans [104] Tandem process for synthesis of quinoxalines [105] Atmospheric oxidation of toluene [106] Cyclohexane oxidation [107] Synthesis of imines from alcohols [108] Synthesis of 2-aminodiphenylamine [109] 9H-Fluorene oxidation [110] Dehydrogenation of ethane in the presence of C02 [111] Decomposition of methane [112] Carbon monoxide oxidation [113]... 

Kumar, R., Garces, L.J., Son, Y., Suib, S.L. and Malz, R.E. (2005) Manganese oxide octahedral molecular sieve catalysts for synthesis of 2-aminodiphenylamine. Journal of Catalysis, 236, 387-391. Opembe, N.N., Son, Y., Sriskandakumar, T. and Suib, S.L. (2008) Kinetics and mechanism of 9H-fluorene oxidation catalyzed by manganese oxide octahedral molecular sieves. ChemSusChem, 1, 182-185. 

A simple synthesis of fluorenes as 4-297 was developed by Schafer and coworkers, also using a combination of a Claisen rearrangement and a carbonyl ene reaction (Scheme 4.63) [100]. Heating 4-295 in xylene at 180 °C led to 4-297 as a single diastereomer in 73 % yield the phenol 4-296 can be assumed as an intermediate, but this could not be detected in the reaction mixture. 

Finally, Larock and coworkers [34] recently reported on an efficient synthesis of 9-alkylidene- and 9-benzylidene-9H-fluorenes 6/1-47, again using 6/1-42 and 6/1-43 as substrates. The best results were obtained with sodium acetate and Bu4NC1, which allowed 6/1-47 to be obtained in 62 % yield. A proposed mechanism is given in Scheme 6/1.9, suggesting a migration of palladium from a vinylic to an arylic position [35]. 

The synthesis of a further group of co-facial dimers containing all-nitrogen donor atoms have been described (Busch, 1980). For example, Ni(n) species of type (142 with R = -(CH2)2-,-(CH2)2,-(CH2)4, m-xylene, or Cy-fluorene) have been isolated (Busch et al., 1981 Herron et al., 1983) these nickel dimers contain the metal ions in square-planar environments. 

Enhanced photovoltaic cell efficiency was achieved via incorporation of highly electron-deficient oxadiazole moieties on side chains of poly(phenylene vinylenejs and poly(fluorene)s <2006SM949>. The synthesis of terminal... 

By the end of the nineteenth century around 600 fluorescent compounds had been identified [3], including fluorescein (A. von Baeyer, 1871), eosine (H. Garo, 1874), and polycyclic aromatic hydrocarbons (C. Liebermann, 1880) [5], Although it is generally accepted that fluorescence markers are relatively new analytical benefits, it is surprising to note that their chemical synthesis is rather old, such as the fluorescein reported by Baeyer, the 2,5-diphenyloxazole by Fisher in 1896, and the fluorene by Berthelot in 1867 [18],... 

In the effort to make pure blue-emitting materials Shim and coworkers [146] synthesized a series of PPV-based copolymers containing carbazole (polymers 95 and 96) and fluorene (polymers 97 and 98) units via Wittig polycondensation. The use of trimethylsilyl substituents, instead of alkoxy groups, eliminates the electron donor influence of the latter and leads to chain distortion that bathochromically shifts the emission (Amax = 480 nm for 95 and 495 nm for 97). In addition, a very high PLQY was found for these polymers in the solid state (64 and 81%, respectively). Single-layer PLEDs fabricated with 95 and 97 (ITO/polymer/Al) showed EL efficiencies of 13 and 32 times higher than MEH-PPV, respectively (see also Ref. [147] for synthesis and PLED studies of polymers 99 and 100) (Chart 2.20). 

SCHEME 2.22 Oxidative coupling synthesis of poly(9,9-dihexyl)fluorene 195. (From Fukuda, M., Sawada, K., and Yoshino, K., Jpn. J. Appl. Phys., Pt. 2 — Letters, 28, L1433, 1989.)... 

SCHEME 2.27 Synthesis of PFs with 4,5-dimethoxy substituents in the fluorene rings. (From Beaupre, S. and Leclerc, M., Macromolecules, 36, 8986, 2003.)... 

SCHEME 2.30 Synthesis of the Frechet-type dendrimer-substituted PFs and fluorene random and alternating copolymers. (From Marsitzky, D., Vestberg, R., Blainey, P., Tang, B.T., Hawker, C.J., and Carter, K.R., J. Am. Chem. Soc., 123, 6965, 2001.)... 

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