191-68-4Relevant academic research and scientific papers
Method for the Synthesis of Dibenzo[g,p]Chrysenes: Domino Friedel-Crafts-Type Cyclization of Difluoroethenes Bearing Two Biaryl Groups
Suzuki, Naoto,Fujita, Takeshi,Ichikawa, Junji
, p. 4984 - 4987 (2015)
Dibenzo[g,p]chrysenes were readily synthesized via the superacid- or TiF4-mediated domino Friedel-Crafts-type cyclization of 1,1-difluoroethenes bearing two biaryl groups, which were easily prepared via the Suzuki-Miyaura coupling of 1,1-difluoro-2,2-diiodoethene or 1-(biphenyl-2-yl)-1-bromo-2,2-difluoroethene. Using this approach, the activation of both vinylic and aromatic C-F bonds was successfully achieved to make new C-C bonds.
High temperatures synthesis of Bowl-shaped subunits of fullerenes - IV. From 4-[9H-fluorenylidene-(9)]-4H-cyclopenta[def]phenanthrene to fluoreno[1,9,8-abcd]corannulene and difluoreno[1,9,8,7-cdefg; 2',1',9',8'-klmno]anthracene
Hagen,Christoph,Zimmermann
, p. 6961 - 6970 (1995)
Fluoreno[1,9,8-abcd]corannulene (4) and difluoreno[1,9,8,7-cdefg;2',1',9',8'-klmno]anthracene (8) have been synthesized by multistage thermal and catalytic dehydrocyclization reactions starting from 4-[9H-fluorenylidene-(9)]-4H-cyclopenta[def]phenanthrene and benzo[p]naphtho[1,8,7-ghi]chrysene, respectively.
Rapid Access to Nanographenes and Fused Heteroaromatics by Palladium-Catalyzed Annulative π-Extension Reaction of Unfunctionalized Aromatics with Diiodobiaryls
Matsuoka, Wataru,Ito, Hideto,Itami, Kenichiro
, p. 12224 - 12228 (2017)
Efficient and rapid access to nanographenes and π-extended fused heteroaromatics is important in materials science. Herein, we report a palladium-catalyzed efficient one-step annulative π-extension (APEX) reaction of polycyclic aromatic hydrocarbons (PAHs) and heteroaromatics, producing various π-extended aromatics. In the presence of a cationic Pd complex, triflic acid, silver pivalate, and diiodobiaryls, diverse unfunctionalized PAHs and heteroaromatics were directly transformed into larger PAHs, nanographenes, and π-extended fused heteroaromatics in a single step. In the reactions that afford [5]helicene substructures, simultaneous dehydrogenative ring closures occur at the fjord regions to form unprecedented larger nanographenes. This successive APEX reaction is notable as it stiches five aryl–aryl bonds by C?H functionalization in a single operation. Moreover, the unique molecular structures, crystal-packing structures, photophysical properties, and frontier molecular orbitals of the thus-formed nanographenes were elucidated.
Contorted tetrabenzoacenes of varied conjugation: Charge transport study with single-crystal field-effect transistors
Huang, Ding-Chi,Kuo, Chi-Hsien,Ho, Man-Tzu,Lin, Bo-Chao,Peng, Wei-Tao,Chao, Ito,Hsu, Chao-Ping,Tao, Yu-Tai
, p. 7935 - 7943 (2017)
A series of contorted and polyfused aromatic tetrabenzoacene derivatives differing in conjugation length were synthesized and characterized. X-ray diffraction revealed the contorted molecular shape, as well as the packing arrangement of these molecules. Thus unsubstituted tetrabenzoacenes showed a shifted or perfect face-to-face π-stacking depending on their conjugation length. The single crystals of these tetrabenzoacenes were used as conducting channels in fabricating field-effect transistors (SCFETs). Tetrabenzotetracene (TBT) exhibited the highest measured mobility, approaching 0.81 cm2 V-1 s-1 (average 0.64 cm2 V-1 s-1) among these molecules. In contrast, theoretical calculation showed that the tetrabenzooctacene (TBO) crystal has large-area, face-to-face π-packing, with the highest intermolecular coupling in the series. The lower charge mobility (average 0.32 cm2 V-1 s-1, highest 0.55 cm2 V-1 s-1) observed was rationalized as a result of possible involvement of delocalized polaron formation due to comparable electronic coupling and reorganization energy in TBO, as supported by the Monte Carlo simulation with this delocalized effect taken into account.
Regio-defined multi-hydroxylation of Dibenzo[g,p]chrysene
Yoshida, Naoki,Kamiguchi, Shinsuke,Sakao, Kazuki,Akasaka, Ryuhei,Fujii, Yoshino,Maruyama, Tomoyuki,Iwasawa, Tetsuo
, (2020)
Regioselective direct tetra-bromination of dibenzo[g,p]chrysene (DBC) is described, involving the synthesis of multi-hydroxyl DBC derivatives. Addition of 16 equiv Br2 to a suspension of DBC in CH2Cl2 enables to singly construct a 2,7,10,15-tetrabromo-DBC. A lithium-bromine exchange event leads the corresponding silyl molecule, and the following oxidation formed a tetra-hydroxyl derivative. Its isomeric tetra-hydroxyl DBC as well as more congested octa-hydroxyl DBC were also singly constructed. These straightforward and simple synthetic routes would provide a general entry for new DBC materials.
Dibenzo [g, p] dibenzo [g, p] decen derivative and a new clean clean sensor derivatives
-
, (2021/11/12)
[Problem] to selectively position the two hydroxyl groups are introduced to clean the sensor 4 [g, p] dibenzo, isomeric products is extremely small, can be made selectively and easily manufacture, and dibenz [g, p] new clean derivative manufactured by the manufacturing method of a sensor. (1) Dibenzo [g, p] [solution] clean sensor brominated, step 4 synthesis of bromide, bromine atoms (2) bromide 4 silylated, silylation process for synthesizing, and, (3) silylation of hydroxy-silyl group by oxidation reaction, synthesis of 2, 7, 10, 15 having a hydroxyl group at step dibenzo [g, p] [g, p] decen tetra- hydroxy dibenzo clean cleaning method for the production of derivatives of the sensor. Also, an oxygen functional group bonded to the dimerization of the fluorenone, 3, 6, 11, 14 and a hydroxyl derivative of [g, p] method for producing clean tetra- hydroxy dibenzo new sensor. [Drawing] no
Build-up of double carbohelicenes using nitroarenes: Dual role of the nitro functionality as an activating and leaving group
Su, Rongchuan,Yang, Yudong,You, Jingsong,Zhou, Fujian,Zhou, Fulin
, p. 7424 - 7428 (2020/09/09)
The construction of double carbohelicenes is highly fascinating yet challenging work. Disclosed herein is a streamlined and simplified synthetic route to double carbohelicenes starting from nitroarenes through sequential nitro-activated ortho-C-H arylation, denitrative alkenylation and intramolecular cyclodehydrogenation. In this synthetic strategy, the nitro group plays a dual role namely as a leaving group for the denitrative alkenylation and as an activating group for ortho-C-H arylation, which is distinct from those of aryl halides in a conventional coupling reaction. In this work, the palladium-catalyzed Heck-type alkenylation of nitroarenes has been presented, in which the conventionally inert Ar-NO2 bond is cleaved. This work provides a novel synthetic strategy for polycyclic aromatic hydrocarbons (PAHs). This journal is
Direct Observation of Aggregation-Induced Emission Mechanism
Corminboeuf, Clémence,Guan, Jianxin,Han, Han,Lin, Kun-Han,Liu, Jitian,Peng, Jie,Prlj, Antonio,Wei, Rong,Yu, Zhihao,Zhao, Dahui,Zheng, Junrong
supporting information, p. 14903 - 14909 (2020/07/04)
The mechanism of aggregation-induced emission, which overcomes the common aggregation-caused quenching problem in organic optoelectronics, is revealed by monitoring the real time structural evolution and dynamics of electronic excited state with frequency and polarization resolved ultrafast UV/IR spectroscopy and theoretical calculations. The formation of Woodward–Hoffmann cyclic intermediates upon ultraviolet excitation is observed in dilute solutions of tetraphenylethylene and its derivatives but not in their respective solid. The ultrafast cyclization provides an efficient nonradiative relaxation pathway through crossing a conical intersection. Without such a reaction mechanism, the electronic excitation is preserved in the molecular solids and the molecule fluoresces efficiently, aided by the very slow intermolecular charge and energy transfers due to the well separated molecular packing arrangement. The mechanisms can be general for tuning the properties of chromophores in different phases for various important applications.
Tailoring Diindenochrysene through Intramolecular Multi-Assemblies by C?F Bond Activation on Aluminum Oxide
Akhmetov, Vladimir,Feofanov, Mikhail,Troyanov, Sergey,Amsharov, Konstantin
supporting information, p. 7607 - 7612 (2019/05/15)
The unique nature of the alumina-mediated cyclodehydrofluorination gives the opportunity to execute the preprogrammed algorithm of the C?C couplings rationally built into a precursor. Such multi-assemblies facilitate the construction of the carbon-skeleton, superseding the conventional step-by-step by the one-pot intramolecular assembly. In this work, the feasibility of the alumina-mediated C?F bond activation approach for multi-assembly is demonstrated on the example of a fundamental bowl-shaped polycyclic aromatic hydrocarbon (diindenochrysene) through the formation of all “missing” C?C bonds at the last step. Beside valuable insights into the reaction mechanism and the design of the precursors, a facile pathway enabling the two-step synthesis of diindenochrysene was elaborated, in which five C?C bonds form in a single synthetic step. It is shown that the relative positions of fluorine atoms play a crucial role in the outcome of the assembly and that governing the substituent positions enables the design of effective precursor molecules “programmed” for the consecutive C?C bond formations. In general, these findings push the state of the field towards the facile synthesis of sophisticated bowl-shaped carbon-based nanostructures through multi-assembly of fluoroarenes.
Regioselective arene homologation through rhenium-catalyzed deoxygenative aromatization of 7-oxabicyclo[2.2.1]hepta-2,5-dienes
Murai, Masahito,Ogita, Takuya,Takai, Kazuhiko
, p. 2332 - 2335 (2019/02/27)
Combined use of oxorhenium catalysts with triphenyl phosphite as an oxygen acceptor allowed efficient deoxygenative aromatization of oxabicyclic dienes. The reaction proceeded under neutral conditions and was compatible with various functional groups. Combining this deoxygenation with regioselective bromination and trapping of the generated aryne with furan resulted in benzannulative π-extension at the periphery of the PAHs. This enabled direct use of unfunctionalized PAHs for extension of π-conjugation. Iteration of the transformations increased the number of fused-benzene rings one at a time, which has the potential to alter the properties of PAHs by fine-tuning the degree of π-conjugation, shape, and edge topology.
