53223-75-9

Upstream product

• 13209-15-9 1,2-bis(dibromomethyl)benzene 
• 159113-90-3 naphthocyclopentadienone 
• 858489-20-0 (2-aminonaphthalen-3-yl)(naphthalen-3-yl)methanone 
• 468751-38-4 ortho-(phenylsulfonylmethyl)benzaldehyde 
• 855879-83-3 N-(3-[2]naphthoyl-[2]naphthyl)-acetamide 
• 109341-49-3 2,3-dihydro-1H-cyclopenta[b]naphthalen-1-one 
• 239-60-1 13H-dibenzo[a,i]fluorene 
• 4599-94-4 13H-dibenzo[a,h]fluoren-13-one 
• 86854-01-5 13H-dibenzo[ai]fluoren-13-one 
• 643-79-8 o-phthalic dicarboxaldehyde 
• 242-47-7 2,3-6,7-dibenzofluorene 
• 216070-60-9 tri(naphthalene-2-yl)methanol 
• 21473-01-8 2-naphthalenylmagnesium bromide 

Downstream Products

• 242-47-7 2,3-6,7-dibenzofluorene 
• 4599-94-4 13H-dibenzo[a,h]fluoren-13-one 

Relevant academic research and scientific papers

Design and synthesis of new stable fluorenyl-based radicals

Organic neutral radicals have long fascinated chemists with a fundamental understanding of structure-reactivity relationships in organic reactions and with applications as new functional materials. However, the elusive nature of these radicals makes the synthesis, isolation, and characterization very challenging. In this work, the synthesis of three long-lived, fluorenyl-based radicals are reported. The geometry and electronic structures of these radicals were systematically investigated with a combination of various experimental methods, besides density functional theory (DFT) calculations, which include X-ray crystallographic analysis, electron spin resonance (ESR), electron nuclear double resonance (ENDOR), cyclic voltammetry, and UV-vis-NIR measurements. Their half-life periods (τ1/2) in air-saturated solution under ambient conditions were also determined. Surprisingly, all three radicals showed remarkable stabilities: τ1/2 = 7, 3.5, and 43 days.

Reversible Friedel-Crafts acyl rearrangements of planar polycyclic aromatic ketones: Dibenzofluorenones

Dibenzofluorenones undergo reversible Friedel-Crafts acyl rearrangements in PPA at elevated temperatures. The Friedel-Crafts acyl rearrangements of 13H-dibenzo[a,i]fluoren-13-one (DBaiF) yield both 13H-dibenzo[a,h]fluoren-13-one (DBahF) and 12H-dibenzo[b,h]fluoren-12-one (DBbhF). DBahF and DBbhF undergo reversible mutual isomerizations, and their ratio depends on the reaction conditions. The O-protonate DBahFH+ plays a pivotal role in the proposed mechanism of the reversible Friedel-Crafts acyl rearrangements. DBahFH+ may undergo proton migration to give two isomeric σ-complexes: σ-13aH-DBahF+ and σ-12aH-DBahF +, leading, via the respective naphthyl naphthoylium ions βCOβN-βN+ and αCOβN-βN+ to O-protonates DBbhFH+ and DBaiFH+, respectively. The regioselectivity of the rearrangement is expressed by the preferred intramolecular beta-electrophilic attack in βCOβN-βN+ and by the preferred alpha-electrophilic attack in αCOβN-βN +, which indicates a thermodynamic control. The proposed mechanism is supported by the results of the DFT calculations of the dibenzofluorenones, their O-protonates, their σ-complexes and their corresponding naphthyl naphthoylium ions at B3LYP/6-311++G(d,p). DBahF and DBaiF are the kinetically controlled products of the Friedel-Crafts acyl rearrangement, while DBbhF is the thermodynamically controlled product. The aromaticity/antiaromaticity notions in dibenzofluorenones and their O-protonates, estimated by calculated HOMA and NICS indices, are discussed. The Royal Society of Chemistry 2013.

Aerobic oxidation of 9H-fluorenes to 9-fluorenones using mono-/multilayer graphene-supported alkaline catalyst

The synthesis of 9-fluorenone derivatives has been achieved in high yield and with high purity by aerobic oxidation of 9H-fluorenes at room temperature in the presence of a graphene-supported KOH composite that acts as a catalyst in N,N-dimethylformamide. The new protocol involves very simple work-up procedures, and the solvent and the catalyst can be recycled and reused. A scaled-up preparative study employing this method was also conducted and showed its advantages of being both cost-effective and environmentally friendly, and has potential for application in industrial processes. Copyright

Rhodium- and iridium-catalyzed dehydrogenative cyclization through double C-H bond cleavages to produce fluorene derivatives

The rhodium-catalyzed cyclization of a series of 2,2-diarylalkanoic acids in the presence of copper acetate as an oxidant smoothly proceeded through double C-H bond cleavages and subsequent decarboxylation to produce the corresponding fluorene derivatives. The direct cyclization of triarylmethanols also took place efficiently by using an iridium catalyst in place of the rhodium, while the hydroxy function was still intact.

Regiospecific synthesis of benzo[b]fluorenones via ring contraction by benzil-benzilic acid rearrangement of benz[a]anthracene-5,6-diones

A regiospecific route to benzo[b]fluorenones is described. The synthesis is based upon a one-pot, regiospecific benzannulation of 1,4-dipolar synthons with naphthoquinone monoketal and ring contraction of the generated benz[a]anthracene-5,6-diones through benzil-benzilic acid rearrangement. Georg Thieme Verlag Stuttgart.