4425-82-5

Usage

Uses

Used in Research Applications:
9-Methylidenefluorene is used as a research compound for studying its mutagenic properties and potential effects on genetic material in various organisms, particularly in Salmonella typhimurium TA98 and TA100 strains. This helps scientists understand the mechanisms of mutagenicity and develop strategies to mitigate the risks associated with mutagenic compounds.

InChI:InChI=1/C14H10/c1-10-11-6-2-4-8-13(11)14-9-5-3-7-12(10)14/h2-9H,1H2

Upstream product

• 86-73-7 9H-fluorene 
• 486-25-9 9-fluorenone 
• 64-17-5 ethanol 
• 188541-54-0 9-chloro-9-methyl-9H-fluorene 
• 59807-88-4 9-(Benzolsulfonylmethyliden)fluoren 
• 67-56-1 methanol 
• 6311-22-4 9-methyl-9H-fluoren-9-ol 
• 7209-38-3 1,4-bis(3-aminopropyl)piperazine 
• 68089-94-1 9-Fluorenylmethyl N-p-chlorphenyl carbamate 
• 50-00-0 formaldehyd 
• 4097-89-6 2,2',2''-triaminotriethylamine 
• 2579-20-6 cis, trans-1,3-dimethylaminocyclohexane 
• 28991-69-7 (9H-fluoren-9-yl)methyl phenylcarbamate 
• 85055-70-5 (9H-fluoren-9-yl)methyl benzoate 

Downstream Products

• 50-00-0 formaldehyd 
• 486-25-9 9-fluorenone 
• 86-73-7 9H-fluorene 
• 2523-37-7 9-methylfluorene 
• 15300-82-0 9,9'-dimethyl-9,9'-bifluorene 
• 79918-18-6 C₂₁H₁₇N₃ 
• 79918-19-7 C₂₁H₁₇N₃O 
• 72853-56-6 Naphtho<2,3-b>fluoranthene-8,13-dione 
• 120-12-7 anthracene 
• 1219940-03-0 C₃₂H₂₆O₄ 
• 1285695-14-8 [(13C)]-9-methyl-9H-fluorene-9-carboxylic acid 
• 1072315-89-9 9-methylfluorene-9-([⁽¹³⁾C]-carbonyl) chloride 
• 4612-64-0 9-(bromomethylene)-9H-fluorene 
• 79918-22-2 (4-Methoxy-phenyl)-phenanthren-9-yl-amine 

Relevant academic research and scientific papers

Photo-induced β-elimination of 9-fluorenylmethanol leading to dibenzofulvene

An effective photo-induced β-elimination of an alcohol leading to a vinyl compound is introduced for the first time. 9-Fluorenylmethanol was irradiated in a solution using a Xe lamp and was efficiently converted to dibenzofulvene (DBF) (9-methylenefluorene) in the absence of base which is necessary in the corresponding ground-state reaction.

Premature removal of N(α)-9-fluorenylmethyloxycarbonyl in thermodynamically controlled enzymatic coupling trials

Incubation of N(α)-Fmoc-ISDR-OH and amino components in mixtures of N,N-dimethylformamide/1,1,1,3,3,3-hexafluoroisopropanol (DMF/HFIP), DMF/2,2,2-trifluoroethanol (TFE) or DMF/1,4-butanediol (BD), 0.2M Tris/HCl buffer, triethylamine (TEA) and apparent pH range 8.0-8.9, led to the undesired formation of variable amounts of dibenzofulvene in the reaction media. Such side reaction, which resulted from a premature Fmoc removal, is minimised by the use 1M buffer or by the increment of the trifluoroethanol proportion in the mixtures.

Rare-earth metal methylidene complexes with Ln3(μ3-CH2)(μ3-Me)(μ2-Me)3 core structure

Trinuclear rare-earth metal methylidene complexes with a Ln3(μ3-CH2)(μ3-Me)(μ2-Me)3 structural motif were synthesized by applying three protocols. Polymeric [LuMe3]n (1-Lu) reacts with the sterically demanding amine H[NSiMe3(Ar)] (Ar = C6H3iPr2-2,6) in tetrahydrofuran via methane elimination to afford isolable monomeric [NSiMe3(Ar)]LuMe2(thf)2 (4-Lu). The formation of trinuclear rare-earth metal tetramethyl methylidene complexes [NSiMe3(Ar)]3Ln3(μ3-CH2)(μ3-Me)(μ2-Me)3(thf)3 (7-Ln; Ln = Y, Ho, Lu) via reaction of [LnMe3]n (1-Ln; Ln = Y, Ho, Lu) with H[NSiMe3(Ar)] is proposed to occur via an "intermediate" species of the type [NSiMe3(Ar)]LnMe2(thf)x and subsequent C-H bond activation. Applying Lappert's concept of Lewis base-induced methylaluminate cleavage, compounds [NSiMe3(Ar)]Ln(AlMe4)2 (5-Ln; Ln = Y, La, Nd, Ho) were converted into methylidene complexes 7-Ln (Ln = Y, Nd, Ho) in the presence of tetrahydrofuran. Similarly, tetramethylgallate complex [NSiMe3(Ar)]Y(GaMe4)2 (6-Y) could be employed as a synthesis precursor for 7-Y. The molecular composition of complexes 4-Ln, 5-Ln, 6-Y and 7-Ln was confirmed by elemental analyses, FTIR spectroscopy, 1H and 13C NMR spectroscopy (except for holmium derivatives) and single-crystal X-ray diffraction. The Tebbe-like reactivity of methylidene complex 7-Nd with 9-fluorenone was assessed affording oxo complex [NSiMe3(Ar)]3Nd3(μ3-O)(μ2-Me)4(thf)3 (8-Nd). The synthesis of 5-Ln yielded [NSiMe3(Ar)]2Ln(AlMe4) (9-Ln; Ln = La, Nd) as minor side-products, which could be obtained in moderate yields when homoleptic Ln(AlMe4)3 were treated with two equivalents of K[NSiMe3(Ar)].

Preservation of the Fmoc protective group under alkaline conditions by using CaCl2. Applications in peptide synthesis

CaCl2 is shown to dramatically increase the lifetime of the Fmoc protective group in alkaline iPrOH-H2O but has little effect on hydrolytic processes. This enables efficient preparation of Fmoc-protected peptide segments by saponification of the corresponding C-terminal methyl or benzyl esters. Similarly, protected peptide segments prepared by Fmoc/tBu solid- phase synthesis can be selectively released from the support by CaCl2- catalyzed alkaline hydrolysis of an N-acylurea-based linker.

Hydrazine hydrate: A new reagent for Fmoc group removal in solid phase peptide synthesis

In solid-phase peptide synthesis using the Fmoc/tBu strategy (SPPS-Fmoc/tBu), an orthogonal protection scheme of amino acids is used; specifically, the alpha-amine group is protected by the 9-fluorenylmethyloxycarbonyl (Fmoc) group, which is removed by weak bases, while side chains are protected by groups that are acid labile. We demonstrated that hydrazine hydrate is an efficient reagent for eliminating the Fmoc group in SPPS-Fmoc/tBu. First, experimental conditions were established for Fmoc group removal from Fmoc-Val-OH in solution. It was determined that the Fmoc group was completely removed with 16% hydrazine hydrate in DMF after 60 min at rt. Second, SPPS-Fmoc/tBu using hydrazine hydrate for Fmoc group removal was standardized. The Fmoc group removal was completed using 16% hydrazine hydrate in DMF for 10 min at rt (twice). When the reaction of Fmoc group removal was microwave-assisted, the reaction only required 30 s to efficiently remove the Fmoc group in SPPS-Fmoc/tBu. The method reported here can be routinely used, and it is equivalent to conventional SPPS-Fmoc/tBu methodologies where 4-methylpiperidine or piperidine is used.

Solid phase synthesis of α-amino squaric acid-containing peptides

A new method has been developed for the synthesis of 3-(1-aminoalkyl)-4-hydroxycyclobut-3-ene-1,2-dione [α-amino squaric acid (α-Asq)]-containing peptides using solid phase peptide synthesis according to an Fmoc protecting group strategy. FmocHN-Gly-[α-Asq]-Oi-Pr was successfully used as a coupling unit in this method, which allowed for the construction of α-Asq-containing hexapeptide libraries including Sq-Gly and Sq-Phe units using the Wang-resin. Peptides containing the α-Asq moiety exhibited inhibitory activity towards a digestive enzyme.

Gallium Methylene

Despite the eminent importance of metal alkylidene species for organic synthesis and industrial catalytic processes, molecular homoleptic metal methylene compounds [M(CH2)n] as the simplest representatives, have remained elusive. Reports on this topic date back to 1955 when polymeric [Li2(CH2)]n and [Mg(CH2)]n were accessed by pyrolysis of methyllithium and dimethylmagnesium, respectively. However, the insoluble salt-like composition of these compounds has impeded their application as valuable reagents. We report that rare-earth metallocene methyl complexes [(C5Me5)2Ln{(μ-Me)2GaMe2}] (Ln=Lu, Y) trigger the formation of homoleptic gallium methylene [Ga8(μ-CH2)12] from trimethylgallium [GaMe3] (Me=methyl) via a cascade C?H bond activation involving the dodecametallic clusters [(C5Me5)6Ln3(μ3-CH2)6Ga9(μ-CH2)9] as crucial intermediates. Such gallium methylene compounds feature a reversible [Ga8(μ-CH2)12]/[Ga6(μ-CH2)9] oligomer switch in donor solvents and act as Schrock-type methylene-transfer reagents.

Specific C-C coupling of the labile diruthenium bridging methylene complex, Cp2Ru2(μ-CH2)(CO)2(MeCN), with diazoalkanes (R2C=N2) leading to alkenyl complexes, Cp2Ru2(μ-CH=CR2)(μ-H)(CO)2, and alkenes, CH2=CR2

Treatment of the labile μ-methylene species, Cp2Ru2(μ-CH2)(CO)2(MeCN) 1, with diazoalkanes results in C-C coupling of the alkylidene units. The reaction of monosubstituted diazoalkanes (N2=CHR) and 4-t-butyldiazocyclohexane gives the μ-alkenyl-μ-hydride complexes, Cp2Ru2(μ-CH=CR2)(μ-H)(CO)2 2, as sole products, whereas the reaction of disubstituted aryldiazoalkanes (N2=CR1R2) produces olefins (CH2=CR1R2) together with mixtures of unidentified organometallic compounds. Labeling experiments using 1-d2 (μ-CD2) and 1-13C (μ-13CH2) reveal that the methylene bridge in 1 is converted to the α-CH and μ-H parts in 2 and the alkylidene part of diazoalkane is incorporated into the β-CR2 part of the alkenyl bridge. The olefinic products should come from a η2-olefin intermediate, Cp2Ru2(η2CH2=CHR)(CO) 2 7, resulting from coupling of the two alkylidene fragments within the coordination sphere of the diruthenium core. It is notable that C-H oxidative addition in 7 takes place prior to free rotation of the η2-olefin ligand as judged by the regiospecificity of the labeling experiments. Thus specific coupling of alkylidene units proceeds under mild conditions and this C-C coupling reaction serves as a model system for the carbon chain propagation step of surface-catalyzed reactions such as catalytic CO hydrogenation.

Synthesis, Structure, and Photophysical and Electrochemical Properties of a π-Stacked Polymer

Dibenzofulvene (DBF) was polymerized using anionic initiators to afford a vinyl polymer. Oligo-(DBF)s having from two to eight side-chain fluorene moieties bearing different chain-terminal groups were isolated by preparative size-exclusion chromatography. The structures of the isolated oligomers were revealed by single-crystal X-ray and 1H NMR analyses. Both in solution and in crystal, the in-chain fluorene moieties stacked on top of each other, while the terminal conformation varied depending on the terminal group. These conformational characteristics were supported by molecular mechanics and dynamics calculations. The oligomers and polymers indicated hypochromism and red shift in UV absorption spectra and exclusive excimer emission in fluorescence spectra. In addition, reduced oxidation potentials were observed for the oligomers in electrochemical analyses, which suggests charge delocalization over the π-stacked electron systems. The photophysical and electrochemical effects increased with the chain length of the oligomers and leveled off around the chain length of an oligomer consisting of five fluorene units.

Interrupted Intramolecular Hydroaminomethylation of N-Protected-2-vinyl Anilines: Novel Access to 3-Substitued Indoles or Indoline-2-ols

A new synthetic alternative to the synthesis of 3-methyl indoles and 3-methyl indoline-2-ols with an excellent atomic economy is presented in this study. It is demonstrated that the intramolecular interrupted hydroaminomethylation (HAM) reaction is a powerful tool for the formation of these compounds, which exhibit wide-ranging biological activity. Several N-Protected-2-vinyl anilines were synthesized and involved in the reaction producing the corresponding 3-methylindole or 3-methyl indoline-2-ol depending on the nature of the N-protecting groups.