191-68-4Relevant articles and documents
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.
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.
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.
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
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.
