4440-33-9

Usage

Uses

Used in Organic Synthesis:
9H-Fluoren-9-imine is used as a building block for the synthesis of various organic compounds due to its reactive imine group and bicyclic structure, which allows for the formation of a variety of complex molecules.
Used in Chemical Research:
9H-Fluoren-9-imine is used as a ligand in coordination chemistry for studying the properties and reactivity of metal complexes, providing insights into the interactions between metal ions and organic ligands.
Used in Pharmaceutical Industry:
9H-Fluoren-9-imine is used as a precursor in the development of new drugs and potential therapeutic agents, leveraging its unique structure and reactivity to create novel pharmaceutical compounds with potential medicinal properties.
Used in Coordination Chemistry:
9H-Fluoren-9-imine is used as a ligand for the synthesis of metal complexes, which can be employed in various applications such as catalysis, sensing, and materials science, due to the compound's ability to form stable complexes with metal ions.

InChI:InChI=1/C13H9N/c14-13-11-7-3-1-5-9(11)10-6-2-4-8-12(10)13/h1-8,14H

Upstream product

• 6630-65-5 9-chlorofluorene 
• 832-80-4 9-diazofluorenone 
• 525-03-1 9-aminofluorene 
• 7664-41-7 ammonia 
• 31859-87-7 N-phenyl-9H-fluoren-9-amine 
• 25022-99-5 9-chloro-9-phenyl-9H-fluorene 
• 746-47-4 tetrabenzo[5.5]fulvalene 
• 101796-89-8 di-fluoren-9-yl-amine 
• 29127-93-3 9-fluorenone O-phenyloxime 
• 1976-60-9 9-(Phenylcarbamoyloximino)-fluoren 
• 681856-02-0 fluoren-9-one-O-(phenylmethyl)oxime 
• 56-23-5 tetrachloromethane 
• 332359-87-2 n-octyl [(9-fluorenylidenamino)oxycarbonyl]formate 
• 71-43-2 benzene 

Downstream Products

• 62614-06-6 diethyl 9-amino-9-fluorenephosphonate 
• 7596-52-3 9-Cyanofluoren-9-amine N-Acetyl derivative 
• 38359-28-3 N-methyl-9H-fluoren-9-amine 
• 1393342-31-8 (2R,3S)-syn-3-diphenylphosphinylamino-2-(9H-fluoren-9-ylidene)amino-3-phenylpropanenitrile 
• 1334168-05-6 anti-3-diphenylphosphinylamino-2-(9H-fluoren-9-ylidene)amino-3-phenylpropanenitrile 

Relevant academic research and scientific papers

Generation and characterization of the selenocysteinyl radical: Direct evidence from time-resolved UV/Vis, electron paramagnetic resonance, and fourier transform infrared spectroscopy

The selenocysteinyl radical 1 has been generated for the first time by laser flash photolysis (λexc = 266 nm) of dimethyl bis(N-tert-butoxycarbonyl)-L-selenocystine 2 and of [(9-fluorenylideneamino)- oxycarbonyl]methyl(N-tert-butoxycarbonyl)-L-selenocysteine 3 in acetonitrile and characterized by time-resolved (TR) UV/Vis, Fourier transform infrared (FTIR), and electron paramagnetic spectroscopy in combination with theoretical methods. A detailed product study was conducted using gas chromatography and one- and two-dimensional NMR spectroscopy. In the case of [(9-fluorenylideneamino) oxycarbonyl]methyl(N-tert-butoxycarbonyl)-L-selenocysteine 3, the (9-fluorenylideneamino)oxycarbonyl moiety serves as a photolabile protection group providing a caged selenocysteinyl radical suitable for biophysical applications. Cleavage of the diselenide bridge or the selenium-carbonyl bond by irradiation is possible in high quantum yields. Because of the lack of a good IR chromophore in the mid-IR region, the selenocysteinyl radical 1 cannot be monitored directly by TR FTIR spectroscopy. TR UV/Vis spectroscopy revealed the formation of the selenocysteinyl radical 1 from both precursors. The selenocysteinyl radical 1 has a lifetime τ ≈ 63 μs and exhibits a strong band located at λmax = 335 nm. Calculated UV absorptions of the selenocysteinyl radical (UB3LYP/6-311G(d,p)) are in good agreement with the experimental results. The use of TR UV/Vis spectroscopy permitted the determination of the decay rates of the selenocysteinyl radical in the presence of two quenchers. The product studies demonstrated the reversible photoreaction of dimethyl bis(N-tert-butoxycarbonyl) -L-selenocystine 2. Products of the photolysis of the caged selenocysteinyl radical precursor 3 are dimethyl bis(N-tert- butoxycarbonyl)-L-selenocystine 2, carbon dioxide, and some further smaller fragments. In addition, the photo-decomposition of the (9-fluorenylideneamino) oxycarbonyl moiety produced 9-fluorenone-oxime 4, 9-fluoren-imine 5, and 6 and 7 as products of the dimerization of two 9-fluorenoneiminoxy radicals 8.

Thermal decomposition of O-benzyl ketoximes; role of reverse radical disproportionation

Thermolyses of seven dialkyl, two alkyl-aryl and two diaryl O-benzyl ketoxime ethers, R1R2C=NOCH2Ph, have been examined in three hydrogen donor solvents: tetralin, 9,10-dihydrophenanthrene, and 9,10-dihydroanthracene. All the oxime ethers gave the products expected from homolytic scission of both the O-C bond (viz., R1R2C=NOH and PhCH3) and N-O bond (viz., R1R2C=NH and PhCH2OH). The yields of these products depended on which solvent was used and the rates of decomposition of the O-benzyl oxime ethers were greater in 9,10-dihydrophenanthrene and 9,10-dihydroanthracene than in tetralin. These results indicated that a reverse radical disproportionation reaction in which a hydrogen atom was transferred from the solvent to the oxime ether, followed by β-scission of the resultant aminoalkyl radical, must be important in the latter two solvents. Benzaldehyde was found to be an additional product from thermolyses conducted in tetralin. This, and other evidence, indicated that another induced decomposition mode involving abstraction of a benzylic hydrogen atom, followed by β-scission of the resulting benzyl radical, became important for some substrates. Participation by minor amounts of enamine tautomers of the oxime ethers was shown to be negligible by comparison of thermolysis data for the O-benzyloxime of bicyclo[3.3.1]nonan-9-one, which cannot give an enamine tautomer, with that of the O-benzyloxime of cyclohexanone.

Thermolyses of O-Phenyl Oxime Ethers. A New Source of Iminyl Radicals and a New Source of Aryloxyl Radicals

Six O-phenyl ketoxime ethers, RR′C=NOPh 1-6, with RR′= diaryl, dialkyl, and arylalkyl, together with N-phenoxybenzimidic acid phenyl ether, PhO(Ph)C=NOPh, 7, have been shown to thermolyze at moderate temperatures with "clean" N-O bond homolyses to yield iminyl and phenoxyl radicals, RR′C=N. and PhO.. Since 1-6 can be synthesized at room temperature, these compounds provide a new and potentially useful source of iminyls for syntheses. The iminyl from 7 undergoes a competition between β-scission, to PhCN and PhO., and cyclization to an oxazole. Rate constants, 106 k/s-1, at 90 °C for 1-6 range from 4.2 (RR′ = 9-fluorenyl) to 180 (RR′ = 9-bicyclononanyl), and that for 7 is 0.61. The estimated activation enthalpies for N-O bond scission are in satisfactory agreement with the results of DFT calculations of N-O bond dissociation enthalpies, BDEs, and represent the first thermochemical data for any reaction yielding iminyl radicals. The small range in k (N-O homolyses) is consistent with the known σ structure of these radicals, and the variations in k and N-O BDEs with changes in RR′ are rationalized in terms of iminyl radical stabilization by hyperconjugation: RR′C=N . ? R.R′C≡N. Calculated N-H BDEs in the corresponding RR′C= NH are also presented.

Characterization of alkoxycarbonyl radicals by step-scan time-resolved infrared spectroscopy

A series of alkoxycarbonyl radicals has been generated by laser flash photolysis (355 nm) of fluorenone oxime alkyl oxalates in carbon tetrachloride and characterized by time-resolved infrared spectroscopy using the step-scan technique. The alkoxycarbonyl radicals (v?C=O = 1802 cm-1 for R = ethyl) generally have a lifetime of several microseconds, decaying by reaction with the solvent to yield esters of chloroformic acid. In some cases, decarboxylation yielding alkyl radicals has also been observed. Thus, photolysis of fluorenone oxime tert-butyl oxalate results in the formation of tert-butoxycarbonyl radicals, which subsequently decay, mainly yielding CO2 and tert-butyl radicals. The benzyloxycarbonyl radical and the acetoneiminoxycarbonyl radical both decarboxylate too rapidly to be detected with our spectrometer (25 ns rise-time). Upon purging the solution with oxygen, the alkoxycarbonyl radicals were efficiently quenched, to yield alkoxycarbonylperoxy radicals (v?C=O = 1845 cm-1 for R = ethyl), which again had a lifetime of the order of several microseconds. A short-lived transient (v? = 1768 cm-1, τ ? 200 ns) is assigned as the carbonyloxy radical 4a on the basis of comparison with time-resolved UV/Vis data. A further product of the photolysis of fluorenone oxime oxalates can be tentatively assigned as the 9-fluorenylideneiminoxy radical 3 (v? = 1670 cm-1), which according to our DFT calculations should show a very intense v?C=N-O,as. = 1665 cm-1. Fluorenone oxime oxalates are compounds well suited as precursors for alkoxycarbonyl radicals, since they are easily synthesized as crystalline solids, show a convenient absorption at λ = 355 nm, and exhibit a high degree of thermal stability.

Electrochemical reduction of oximes in aprotic media

The electrochemical reduction in N,N-dimethylformamide of (Z)- and (E)-benzaldoximes, derivatives thereof and some ketoximes has been investigated. The bases electrogenerated during the reduction of the benzaldoximes and their derivatives induce a catalytic elimination reaction producing benzonitrile. Two mechanisms are discussed, one in which the electrogenerated base eliminates water from the incoming substrate and one in which the base abstracts a proton from the intermediate benzaldimine radical with formation of benzonitrile radical anion; this radical anion then reduces the incoming substrate. The electrogenerated base formed during the reduction of the ketoximes deprotonates the oxime to the less reducible oxime anion. During the reduction of an acylated oxime, the parent oxime is formed, probably by cleavage induced by the electrogenerated base, but direct cleavage of the radical anion to the oxime might be possible. Acta Chemica Scandinavica 1998.

Thermal ring enlargement of aromatic cyclopentadienylidene iminyl radicals. Intramolecular radical addition to the N atom of nitriles results in high yields of aza-aromatics

It has been demonstrated that ketiminyl radicals, formed at high temperatures (1000 °C, 0.3 s) in oxygen-free nitrogen from phenylhydrazones of benz-anellated cyclopentadienones (fluorenone (9a), methanophenanthrenone (9b)), yield into phenanthridine (8a) and benzo[lmn]-phenanthridine (8b) in yields > 60%. The results point to a predominant addition of intermediately generated phenyl type radicals 5 to the N atom of the nitrile groups followed by bimolecular H-abstraction of the cyclic imidoyl radicals to 8.

Laser flash photolysis of carbamates derived from 9-fluorenone oxime

The photochemistry of carbamates derived from 9-fluorenone oxime was investigated by laser flash photolysis and by product studies. Primary photocleavage of the excited carbamates leads to decarboxylation and concomitant generation of the 9-fluorenone ketimine-N-yl radical and an amino radical. In the case of 9-fluorenylideneamino N-(2,5-dimethoxyphenyl)carbamate the presence of 1,4-dimethoxybenzene in the product mixture as well as spectroscopic and kinetic evidence points to the intermediary formation of triplet (2,5-dimethoxyphenyl)nitrene, which in acetonitrile dimerizes to the corresponding azo compound. Analogously, the formation of trans-azobenzene upon photolysis of 9-fluorenylideneamino N-phenylcarbamate indicates the intermediacy of parent triplet phenylnitrene, which, until now, had not been observed in solution at ambient temperature.

Intramolecular Trapping of a Ketenimine Carbene Formed on Flash Vacuum Pyrolysis of 3-Phenylimino-3H-indazole and 3-Phenyliminoisobenzofuran-1-one

Flash vacuum pyrolysis of 3-phenylimino-3H-indazole yielded biphenylene, benzonitrile and, by loss of dinitrogen followed by intramolecular trapping of a ketenimine carbene intermediate, the isomers fluorenimine, phenanthridine and 2-phenylbenzonitrile.Pyrolysis of 3-phenyliminoisobenzofuran-1-one gave the same five products together with N-phenylphthalimide.It is proposed that the same ketenimine carbene intermediate is involved in the two reactions.Pyrolysis of 3-o-tolylimino- and 3-benzylimino-isobenzofuran-1-one led to fragmentation without intramolecular trapping.Pyrolysis of 3-t-butyliminoisobenzofuran-1-one gave o-cyanobenzoic acid.

The Electrochemical Reduction of Fluorenone Tosylhydrazone: Evidence Consistent with Formation of the Tosyl Nitrene Anion Radical

Fluorenone tosylhydrazone (Fl=NNHTs) undergoes one-electron reductive dehydrogenation in DMF-0.1 F (n-Bu)4NClO4 to give hydrogen and its conjugate base Fl=NN-Ts as products.Fl=NN-Ts is subsequently reduced at more negative potential to a dianion radical (Fl=NNTs dianion radical) that is stable on the cyclic voltammetric time scale.On the coulometric time scale or in the presence of added proton donors (pKa ca.29), Fl=NNTs dianion radical decomposes to give FlHNH2 and TsNH2 as the principal products.A pathway is proposed for the reaction of Fl=NNTs dianion radical which involves rate-determining proton abstraction by the nitrogen atom α to the fluorene moiety.Cyclic voltammetric and chronoamperometric data are presented which are consistent with the formation of the tosyl nitrene anion radical as a short-lived, unobserved intermediate.

Stereochemical and Mechanistic Aspects of the Base-catalysed Decomposition of N-Alkyloxaziridines to form NH Ketimines

The synthesis of a new range of oxaziridines (18)-(23), (30)-(35) by peracid oxidation of diaryl ketimines and aryl aldimines is reported.Relatively stable NH ketimine products (24)-(27) have been isolated from base-catalysed decomposition of the oxaziridines (18)-(20), (30)-(35) and a primary kinetic isotope effect (ca. kH/kD 6.0) was observed during decomposition of the oxaziridine trans-(31).The trans-oxaziridines (31)-(35) were found to decompose at a faster rate than the corresponding cis isomers.The relative rates of base-catalysed decomposition of oxaziridine stereoisomers are consistent with a mechanism involving an α-C-H proton abstraction mechanism.