T:Toxic;218-01-9Relevant articles and documents
Regiospecifically Fluorinated Polycyclic Aromatic Hydrocarbons via Julia-Kocienski Olefination and Oxidative Photocyclization. Effect of Fluorine Atom Substitution on Molecular Shape
Banerjee, Shaibal,Sinha, Saikat,Pradhan, Padmanava,Caruso, Alessio,Liebowitz, Daniel,Parrish, Damon,Rossi, Miriam,Zajc, Barbara
, p. 3983 - 3993 (2016)
A modular synthesis of regiospecifically fluorinated polycyclic aromatic hydrocarbons (PAHs) is described. 1,2-Diarylfluoroalkenes, synthesized via Julia-Kocienski olefination (70-99% yields), were converted to isomeric 5- and 6-fluorobenzo[c]phenanthrene, 5-and 6-fluorochrysene, and 9- and 10-benzo[g]chrysene (66-83% yields) by oxidative photocyclization. Photocyclization to 6-fluorochrysene proceeded more slowly than conversion of 1-styrylnaphthalene to chrysene. Higher fluoroalkene dilution led to a more rapid cyclization. Therefore, photocyclizations were performed at higher dilutions. To evaluate the effect of fluorine atom on molecular shapes, X-ray data for 5- and 6-fluorobenzo[c]phenanthrene, 6-fluorochrysene, 9- and 10-fluorobenzo[g]chrysene, and unfluorinated chrysene as well as benzo[g]chrysene were obtained and compared. The fluorine atom caused a small deviation from planarity in the chrysene series and decreased nonplanarity in the benzo[c]phenanthrene derivatives, but its influence was most pronounced in the benzo[g]chrysene series. A remarkable flattening of the molecule was observed in 9-fluorobenzo[g]chrysene, where the short 2.055 ? interatomic distance between bay-region F-9 and H-8, downfield shift of H-8, and a 26.1 Hz coupling between F-9 and C-8 indicate a possible F-9···H-8 hydrogen bond. In addition, in 9-fluorobenzo[g]chrysene, the stacking distance is short at 3.365 ? and there is an additional interaction between the C-11-H and C-10a of a nearby molecule that is almost perpendicular.
Alumina-Mediated π-Activation of Alkynes
Akhmetov, Vladimir,Amsharov, Konstantin,Feofanov, Mikhail,Sharapa, Dmitry I.
supporting information, p. 15420 - 15426 (2021/09/30)
The ability to induce powerful atom-economic transformation of alkynes is the key feature of carbophilic π-Lewis acids such as gold- and platinum-based catalysts. The unique catalytic activity of these compounds in electrophilic activations of alkynes is explained through relativistic effects, enabling efficient orbital overlapping with π-systems. For this reason, it is believed that noble metals are indispensable components in the catalysis of such reactions. In this study, we report that thermally activated γ-Al2O3activates enynes, diynes, and arene-ynes in a manner enabling reactions that were typically assigned to the softest π-Lewis acids, while some were known to be triggered exclusively by gold catalysts. We demonstrate the scope of these transformations and suggest a qualitative explanation of this phenomenon based on the Dewar-Chatt-Duncanson model confirmed by density functional theory calculations.
Chrysene-Based Blue Emitters
Nathusius, Marvin,Ejlli, Barbara,Rominger, Frank,Freudenberg, Jan,Bunz, Uwe H. F.,Müllen, Klaus
, p. 15089 - 15093 (2020/10/21)
Chrysene and its bisbenzannulated homologue, naphtho[2,3-c]tetraphene, were synthesized through a PtCl2-catalyzed cyclization of alkynes, which also furnished corresponding biaryls subsequent to a Glaser coupling reaction of the starting alkynes. The optoelectronic properties of 5,5′-bichrysenyl and 6,6′-binaphtho[2,3-c]tetraphene were compared to their chrysene-based “monomers”. Oxidative cyclodehydrogenations of bichrysenyl and its higher homologue towards large nanographenes were also investigated.
Construction of Phenanthrenes and Chrysenes from β-Bromovinylarenes via Aryne Diels-Alder Reaction/Aromatization
Singh, Vikram,Verma, Ram Subhawan,Khatana, Anil K.,Tiwari, Bhoopendra
, p. 14161 - 14167 (2019/10/28)
A highly efficient transition-metal-free general method for the synthesis of polycyclic aromatic hydrocarbons like phenanthrenes and chrysenes (and tetraphene) from β-bromovinylarenes and arynes has been developed. The reactions proceed via an aryne Diels-Alder (ADA) reaction, followed by a facile aromatization. This is the first report on direct construction of chrysenes (and tetraphene) using the ADA approach. Unlike the literature method which is limited to only 9/10-substituted derivatives, this method gives access to a wide variety of functionalized phenanthrenes.
A novel and efficient synthesis of phenanthrene derivatives via palladium/norbornadiene-catalyzed domino one-pot reaction
Zhong, Yue,Wu, Wen-Yu,Yu, Shao-Peng,Fan, Tian-Yuan,Yu, Hai-Tao,Li, Nian-Guang,Shi, Zhi-Hao,Tang, Yu-Ping,Duan, Jin-Ao
supporting information, p. 291 - 298 (2019/02/20)
Herein we report a novel palladium-catalyzed reaction that results in phenanthrene derivatives using aryl iodides, ortho-bromoben-zoyl chlorides and norbornadiene in one pot. This dramatic transformation undergoes ortho-C–H activation, decarbonylation and subsequent a retro-Diels–Alder process. Pleasantly, this protocol has a wider substrate range, shorter reaction times and higher yields of products than previously reported methods.
Oxidative, Iodoarene-Catalyzed Intramolecular Alkene Arylation for the Synthesis of Polycyclic Aromatic Hydrocarbons
Zhao, Zhensheng,Britt, Liam H.,Murphy, Graham K.
, p. 17002 - 17005 (2018/11/01)
A catalytic, metal-free and chemoselective oxidative intramolecular coupling of arene and alkene C?H bonds is reported. The active hypervalent iodine (HVI) reagent, generated catalytically in situ from iodotoluene and meta-chloroperoxybenzoic acid (m-CPBA), reacts with o-vinylbiphenyls to generate polyaromatic hydrocarbons in up to 95 % yield. Experimental evidence suggests the reactions proceed though vinyliodonium and, possibly, vinylenephenonium intermediates.
Further insight into the photochemical behavior of 3-aryl-N-(arylsulfonyl)propiolamides: tunable synthetic route to phenanthrenes
Chen, Ming,Zhao, Xinxin,Yang, Chao,Wang, Yanpei,Xia, Wujiong
, p. 12022 - 12026 (2017/03/01)
Reported herein is further insight into the photochemical behaviour of 3-aryl-N-(arylsulfonyl)-propiolamides, which provides a straightforward way to access meaningful phenanthrenes. Mechanistic investigation indicated that aryl migration, C-C coupling, 1,3-hydrogen shift, desulfonylation and elimination were involved in the process. Moreover, this protocol allowed for scale-up using a flow reactor.
Convenient Phenacene Synthesis by Sequentially Performed Wittig Reaction and Mallory Photocyclization Using Continuous-Flow Techniques
Okamoto, Hideki,Takahashi, Haruhiko,Takane, Takamitsu,Nishiyama, Yasuhiro,Kakiuchi, Kiyomi,Gohda, Shin,Yamaji, Minoru
, p. 2949 - 2957 (2017/06/27)
Various phenacenes possessing chrysene, picene, and fulminene frameworks were prepared by using a continuous-flow synthetic protocol in which Wittig reaction affording diarylethenes and their Mallory photocyclization producing phenacene skeletons were sequentially performed. The Wittig reaction solution, containing the diaryl ethene obtained from an arylaldehyde and an arylmethyltriphenylphosphonium salt, was mixed with an iodine solution in the flow system and, subsequently, the solution was subjected to the photoreaction. Desired phenacenes were obtained with high to moderate chemical yield. For the present protocol, isolation of the intermediary diarylethene, which is the key precursor of the phenacene, is unnecessary. The approach provides a convenient method to supply a variety of phenacene samples, which are needed for initial systematic surveys in material science.
Facile Synthesis of Polycyclic Aromatic Hydrocarbons: Br?nsted Acid Catalyzed Dehydrative Cycloaromatization of Carbonyl Compounds in 1,1,1,3,3,3-Hexafluoropropan-2-ol
Fujita, Takeshi,Takahashi, Ikko,Hayashi, Masaki,Wang, Jingchen,Fuchibe, Kohei,Ichikawa, Junji
, p. 262 - 265 (2017/01/24)
The cycloaromatization of aromatic aldehydes and ketones was readily achieved by using a Br?nsted acid catalyst in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP). In the presence of a catalytic amount of trifluoromethanesulfonic acid, biaryl-2-ylacetaldehydes and 2-benzylbenzaldehydes underwent sequential intramolecular cationic cyclization and dehydration to afford phenacenes and acenes, respectively. Furthermore, biaryl-2-ylacetaldehydes bearing a cyclopentene moiety at the α-position underwent unprecedented cycloaromatization including ring expansion to afford triphenylenes. HFIP effectively promoted the cyclizations by suppressing side reactions presumably as a result of stabilization of the cationic intermediates.
A method of chemical synthesis * ring
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Paragraph 0024; 0025, (2018/02/04)
The invention discloses a method for chemically compounding (img file='DDA0000712956880000012. TIF' wi='52' he='60'/) rings. The method for preparing the formula I (img file='DDA0000712956880000012. TIF' wi='52' he='60'/) rings (which also is a (img file='DDA0000712956880000013. TIF' wi='55' he='57'/) ring) comprises the steps that 2 - (4 - alkoxy phenyl) ethinyl acetophenone in the formula II and 2-alkynylbenzaldehydes in a formula III are dissolved in organic solvent, then generate a cyclization reaction after adding an accelerant in a system to stir, and a compound showed in the formula I is obtained after reacting. The method for chemically compounding the (img file='DDA0000712956880000012. TIF' wi='52' he='60'/) rings is a one-pot synthesis method, compounds the compound in a manual way for the first time, and raw materials in the method are low in cost and are easy to obtain, are simple in reaction operation, mild in conditions and suitable for large-scale preparation, and have important application value. (img file='DDA0000712956880000011. TIF' wi='1430' he='485'/).
