Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno‐fluorènes XI [1]. Trans‐Fluorénacène et dérivés méthylés

Abstract

Re'sumd. On decrit la prdparation, 8. partir de la dibromo-2,5-t6rCphtaloph6none et de quelques-uns de ses derives mithylgs, par dishydrobromation accompagn6e d'une double cyclisation, de la trans-fluor6nachne-dione (dioxo-6,12-dihydro-6,12-ind6no [l, 2-b] fluorkne) et de quelques d6riv6s m6thyl6s. Ces dicitones polycycliques sont colorees en orang6, rouge ou violet, et cuvables. Leur reduction selon WOLFF-KISHNER fournit les hydrocarbures correspondants.Le dihydro-6,lZ-indCno [l, 2-b] fluorbne (I) (trans-fluorCnadne en nomenclature abr6g6e [2]) a CtC dCcrit pour la premibre fois par DEUSCHEL [3], qui l'a synth6tisC en deux 6tapes B partir du cyclohexkne et du$-xyl&ne avec un rendement de 13,4% de la thCorie. Dans la suite, EBEL 8r DEUSCHEL [4] ont amClior6 la mCthode en simplifiant la technique et abouti en quatre &tapes (rendement global 68,5%) B la dione correspondante, soit au dioxo-6,12-dihydrod,lZ-indCno [1, 2-b] fluorkne (11) ou trans-fluorCnache-dione.

Bridging the Gap between Polyfluorene and Ladder-Poly-p-phenylene: Synthesis and Characterization of Poly-2,8-indenofluorene

“…The synthesis of polyindenofluorene started from the well-known indenofluorene ( 5 ) , (Scheme ), which was tetraalkylated using n -butyllithium and alkyl bromides. The resulting 6,6‘,12,12‘-tetraalkylindenofluorenes (6a,b) were selectively brominated in 2,8-positions with copper(II) bromide on an aluminum oxide matrix in carbon tetrachloride. , The reaction progress was monitored by FD mass spectroscopy and led to the desired 2,8-dibromo monomer 7a,b in 99% yield.…”

Molecular packing and morphological stability of dihydro-indeno[1,2-b]fluorenes in the context of their substitution pattern

“…Alternatively, alkylated IFs have been synthesized using a different strategy based on the work of Deuschel and Chardonnens (Route B). 26,27 Following this reaction sequence, the terephthalic ester 1 was saponied and the resulting terephthalic acid 3 subsequently cyclized to the diketone 4 using sulfuric acid. 28 The diketone 4 was reduced to the dihy-droindenouorene 5 in a Wolff-Kishner reaction 28 and aerwards alkylated using a reaction protocol by Lardíes et al 29 The synthesis of the mixed substituted dihydroindeno-uorene derivatives was achieved starting from 2-bromo uorene 8 (Scheme 2).…”

1,4-Dibromo-2,5-di-p-toluoylbenzene

“…The title compund was synthesized according to the published procedure (Chardonnens & Salamin, 1968). Colourless blocks were obtained by dissolving it (0.5 g) in tetrahydrofuran (20 ml) and evaporating the solvent slowly at room temperature for about 10 d.…”