1556-99-6

Usage

Chemical Description

4-methylfluorene is a condensed aromatic nucleus obtained from the cyclodehydrogenation of 2,2’-dimethylbiphenyl.

InChI:InChI=1/C14H12/c1-10-5-4-7-12-9-11-6-2-3-8-13(11)14(10)12/h2-8H,9H2,1H3

Upstream product

• 4269-05-0 4-methyl-9H-fluoren-9-one 
• 874530-20-8 4-methyl-1,4,4a,9a-tetrahydro-fluorene 
• 605-39-0 2,2'-dimethyl-1,1'-biphenyl 
• 1859-10-5 4-methylfluoren-9-ol 
• 954-16-5 2,4,6-Trimethylbenzophenon 
• 91612-00-9 2,7-bis(tert-butyl)-4-methyl fluorene 
• 86659-18-9 4a-methyl-4aH-fluorene 
• 6954-55-8 fluorene-4-carboxylic acid 
• 107456-41-7 4-Chlormethylfluoren 
• 694-80-4 2-bromo-1-chlorobenzene 
• 21450-64-6 (2,6-dimethylphenyl)magnesium bromide 
• 615-41-8 2-iodochlorobenzene 
• 136859-32-0 toluene-4-sulfonic acid 2-iodo-phenyl ester 
• 583-55-1 1-Bromo-2-iodobenzene 

Downstream Products

• 186131-58-8 bis-(4-methyl-9H-fluoren-9-yl)-diphenyl-silane 

Relevant academic research and scientific papers

Annulative tandem reactions based on Pd0/tBu3P- catalyzed cross-coupling and C(sp3)-H bond activation

(Chemical Equation Presented) All together now: Pd0/tBu 3P-catalyzed annulative tandem reactions of 1,2-dihalobenzenes were carried out with hindered Grignard reagents. This new type of tandem reaction is believed to occur through cross-coupling followed by cyclization with C(sp 3)-H bond activation as the key step and allows one-step access to potentially useful substituted fluorenes in high yield from readily available 1,2-dibromobenzenes and 1-bromo-2-iodobenzene.

Palladium-Catalyzed Formal [4 + 1] Annulation via Metal Carbene Migratory Insertion and C(sp2)-H Bond Functionalization

A highly efficient and operationally simple palladium-catalyzed formal [4 + 1] annulation reaction has been developed. The reaction is featured by the formation of two different C-C bonds on a carbenic center. It represents a concise method for the synthesis of a wide range of polycyclic aromatic hydrocarbons (PAHs) and 1H-indenes with easily available (trimethylsilyl)diazomethane as the carbene source. Metal carbene migratory insertion and C(sp2)-H bond activation are proposed as the key steps in this transformation. The reaction further demonstrates the versatility of the carbene-based coupling in combination with various transition-metal-catalyzed transformations.

Efficient palladium-catalyzed C(sp2)-H activation towards the synthesis of fluorenes

A facile protocol for the synthesis of fluorene derivatives has been developed through palladium-catalyzed cyclization of 2′-halo-diarylmethanes via activation of arylic C-H bonds. The reactions occurred smoothly and allowed both electron-rich and electron-deficient substrates to convert into their corresponding fluorenes in good to excellent yields. Studies revealed that this Pd-catalyzed cyclization was also available for the substrates of 2′-chloro-diarylmethanes and no catalyst poisoning occurred for 2′-iodo-diphenylmethane.

Synthesis of Fluorenes Starting from 2-Iodobiphenyls and CH2Br2 through Palladium-Catalyzed Dual C-C Bond Formation

A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C-C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C-H activation.

POLYMER AND ORGANIC ELECTRONIC DEVICE

A polymer comprising a repeat unit of formula (I): wherein R1 in each occurrence is independently H or a substituent, and the two groups R1 may be linked to form a ring; R2 in each occurrence is independently a substituent; Ar1 in each occurrence is independently an aryl or heteroaryl group that may be unsubstituted or substituted with one or more substituents; R3 in each occurrence is independently a substituent; each n independently is 0, 1, 2 or 3 with the proviso that at least one n=1; and each m is independently 0 or 1. The polymer may be a light-emitting 103 of an organic light-emitting device.

Gold(I) carbenes by retro-buchner reaction: Generation and fate

The fate of the aryl gold(I) carbenes generated by retro-Buchner reaction of ortho-substituted 7-aryl-1,3,5-cycloheptatrienes is dependent on the constitution of the ortho substituent. Indenes and fluorenes are obtained by intramolecular reaction of highly electrophilic gold(I) carbenes with alkenes and arenes. According to density functional theory calculations, the gold-catalyzed retro-Buchner process occurs stepwise, although the two carbon-carbon cleavages occur on a rather flat potential energy surface.

Pd(OAc)2-catalyzed domino reactions of 1,2-dihaloarenes and 2-haloaryl arenesulfonates with Grignard reagents: efficient synthesis of substituted fluorenes

Pd(OAc)2-catalyzed domino reactions of 1,2-dihalobenzenes and 2-haloaryl arenesulfonates with hindered Grignard reagents to form substituted fluorenes, which are believed to occur through palladium associated aryne intermediates, are described. Such palladium associated aryne reaction pathway was found to be favored by omitting the use of phosphine and N-heterocyclic carbene ligands for palladium catalysts and with better leaving groups. Our study suggested that Pd(leaving group)X associated arynes should be formed first and the sp3 C-H activation preferentially occurred at benzylic C-(1°)H bonds. The work described here provides a high yield, one-step access to substituted fluorenes from readily available 1,2-dihalobenzenes and 2-haloaryl arenesulfonates and hindered Grignard reagents, and this substituted fluorene-making method may find applications in the preparation of substituted fluorene-containing molecules including polymers.

Pd(OAc)2-catalyzed Domino reactions of 1-chloro-2-haloarenes and 2-haloaryl tosylates with hindered Grignard reagents via palladium-associated arynes

(Chemical Equation Presented) The palladium-associated aryne generation strategy and Pd(OAc)2-catalyzed annulative Domino reactions of 1-chloro-2-halobenzenes and 2-haloaryl tosylates with hindered Grignard reagents via palladium-associated arynes are described. The palladium-associated aryne generation strategy described here not only allows the high yield, one-step access to potentially useful substituted fluorenes from readily available 1-chloro-2-halobenzenes and 2-haloaryl tosylates, but may also lead to the development of other tandem reactions based on these readily available ortho leaving group bearing haloarenes.

Characterization of polycyclic aromatic hydrocarbon particulate and gaseous emissions from polystyrene combustion

The partitioning of polycyclic aromatic hydrocarbons (PAHs) between the particulate and gaseous phases resulting from the combustion of polystyrene was studied. A vertical tubular flow furnace was used to incinerate polystyrene spheres (100-300 μm) at different combustion temperatures (800- 1200 °C) to determine the effect of temperature and polystyrene feed size on the particulate and gaseous emissions and their chemical composition. The furnace reactor exhaust was sampled using real-time instruments (differential mobility particle sizer and/or optical particle counter) to determine the particle size distribution. For chemical composition analyses, the particles were either collected on Teflon filters or split into eight size fractions using a cascade impactor with filter media substrates, while the gaseous products were collected on XAD-2 adsorbent. Gas chromatography/mass spectroscopy (GC/MS) was used to identify and quantify the specific PAH species, their partitioning between the gas and particulate phases, and their distribution as a function of emission particle size. The total mass and number of PAH species in both the particulate and gas phases were found to decrease with increasing incineration temperature and decreasing polystyrene feed size, while the mean diameter of the particles increases with increasing incineration temperature and decreasing feed size. In addition, the PAH species in the particulate phase were found to be concentrated in the smaller aerosol sizes. The experimental results have been analyzed to elucidate the formation mechanisms of PAHs and particles during polystyrene combustion. The implications of these results are also discussed with respect to the control of PAH emissions from municipal waste-to-energy incineration systems. The partitioning of polycyclic aromatic hydrocarbons (PAHs) between particulate and gaseous phases resulting from the combustion of polystyrene was studied. A vertical tubular flow furnace was used to incinerate polystyrene spheres to determine the effect of temperature and polystyrene feed size on the particulate and gaseous emissions and their chemical composition. The furnace reactor exhaust was sampled using real-time instruments to determine the particle size distribution. The total mass and number of PAH species in both the particulate and gas phases were found to decrease with increasing incineration temperature and decreasing polystyrene feed size, while the mean diameter of the particles increases with increasing incineration temperature and decreasing feed size. In addition, the PAH species in the particulate phase were found to be concentrated in the smaller aerosol sizes.

A New Route for the Preparation of Fluorene Derivatives Using Friedel-Crafts Intramolecular Cyclobenzylation

A convenient preparation of fluorene derivatives based on a novel Friedel-Crafts intramolecular cyclobenzylation, involving the action of Cl2CHOMe and TiCl4, on a variety of biphenyls (constructed such that electrophilic substitution occurs ortho to the biphenyl linkage), is described.