192-51-8Relevant articles and documents
Chemisorption-Induced Formation of Biphenylene Dimer on Ag(111)
Chen, Qifan,Guo, Dezhou,Han, Dong,Huang, Jianmin,Jelínek, Pavel,Matěj, Adam,McEwen, Jean-Sabin,Wang, Tao,Xu, Qian,Zeng, Zhiwen,Zhao, Aidi,Zhu, Junfa,de Oteyza, Dimas G.
, p. 723 - 732 (2022/01/19)
We report an example that demonstrates the clear interdependence between surface-supported reactions and molecular-adsorption configurations. Two biphenyl-based molecules with two and four bromine substituents, i.e., 2,2′-dibromobiphenyl (DBBP) and 2,2′,6,6′-tetrabromo-1,1′-biphenyl (TBBP), show completely different reaction pathways on a Ag(111) surface, leading to the selective formation of dibenzo[e,l]pyrene and biphenylene dimer, respectively. By combining low-temperature scanning tunneling microscopy, synchrotron radiation photoemission spectroscopy, and density functional theory calculations, we unravel the underlying reaction mechanism. After debromination, a biradical biphenyl can be stabilized by surface Ag adatoms, while a four-radical biphenyl undergoes spontaneous intramolecular annulation due to its extreme instability on Ag(111). Such different chemisorption-induced precursor states between DBBP and TBBP consequently lead to different reaction pathways after further annealing. In addition, using bond-resolving scanning tunneling microscopy and scanning tunneling spectroscopy, we determine with atomic precision the bond-length alternation of the biphenylene dimer product, which contains 4-, 6-, and 8-membered rings. The 4-membered ring units turn out to be radialene structures.
Modular metal-free catalytic radical annulation of cyclic diaryliodoniums to access π-extended arenes
Zhu, Daqian,Peng, Hui,Sun, Yameng,Wu, Zhouming,Wang, Yun,Luo, Bingling,Yu, Tiantian,Hu, Yumin,Huang, Peng,Wen, Shijun
supporting information, p. 1972 - 1977 (2021/03/26)
Polycyclic aromatic hydrocarbons (PAHs) are of increasing importance in the advanced material field. Cyclic diaryliodonium salts are non-toxic and environmentally benign arylating reagents. Here, we describe an alkylamine-mediated free radical intramolecular annulation to access PAHs under environmentally friendly conditions. On modulating substituents and their positions in the iodoniums, the free radical reaction controllably underwent three types of cyclization including ring contraction and ring switch to form tricyclic and tetracyclic frameworks of PAHs. Preliminary mechanistic studies implied that alkylamines initiated a radical pathway to complete the cyclization efficiently. Moreover, these acquired products were further converted into diverse complex graphene segments.
Synthesis of Polybenzoacenes: Annulative Dimerization of Phenylene Triflate by Twofold C?H Activation
Uryu, Mizuho,Hiraga, Taito,Koga, Yoshito,Saito, Yutaro,Murakami, Kei,Itami, Kenichiro
supporting information, p. 6551 - 6554 (2020/04/10)
Polycyclic aromatic hydrocarbons (PAHs) represent an emerging class of π-conjugated molecules in the area of optoelectronic devices and materials. Unprecedented synthetic routes to various PAHs from simple phenol derivatives by a palladium-catalyzed annulative dimerization of phenylene triflate through twofold inter- and intramolecular C?H activation have been established. The initially formed partially fused PAHs can be smoothly transformed into a variety of fully fused PAHs by the Scholl reaction. Furthermore, the reactions of phenanthrene-substituted aryl triflates proceeded regioselectively. The findings inspired the development of a rapid and efficient synthesis of polybenzoacene derivatives. This study not only allows transformation of phenyl triflates, but also discloses a new retrosynthetic strategy towards PAHs, especially polybenzoacenes.
An aryl substituted tris of compounds of preparation method and its application
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Paragraph 0018; 0052-0054, (2019/07/08)
The invention discloses an aryl substituted tris of compounds of preparation method and its application. The preparation method process is: in formula I compound as a raw material, under protection of inert gas, in the organic solution, the participation of the inorganic base, to control the reaction temperature 70 - 160 °C, raw material process for the catalytic reaction to obtain aryl substituted tris benzene compound; type I structure of the compound is: Wherein R1 For the H atom, alkyl, alkoxy, haloalkyl oxy, F or Cl, R2 For the H atom, alkyl, alkoxy, haloalkyl oxy, F or Cl, and R1 And R2 In at least one is a H atom. This synthetic route has not seen the literature reports, and the cost of raw material; unit of simple operation, low equipment requirements, is suitable for the rapid construction of tris of compounds and fused ring compound.
Bottom-up Construction of π-Extended Arenes by a Palladium-Catalyzed Annulative Dimerization of o-Iodobiaryl Compounds
Zhu, Chendan,Wang, Di,Wang, Dingyi,Zhao, Yue,Sun, Wei-Yin,Shi, Zhuangzhi
supporting information, p. 8848 - 8853 (2018/05/08)
A straightforward method was developed for construction of aromatic compounds with a triphenylene core. The method involves Pd-catalyzed annulative dimerization of o-iodobiaryl compounds by double C?I and C?H bond cleavage steps. Simple reaction conditions are needed, requiring neither a ligand nor an oxidant, and the reaction tolerates a wide range of coupling partners without compromising efficiency or scalability. Significantly, the tetrachloro-substituted synthon, 1,6,11-trichloro-4-(4-chlorophenyl)triphenylene, can be generated and used to prepare a series of fully fused, small graphene nanoribbons by a late-stage arylation with arylboronic acids and a subsequent Scholl reaction. The synthetic strategy enables bottom-up access to extended π-systems in a controlled manner.
The Rolling-Up of Oligophenylenes to Nanographenes by a HF-Zipping Approach
Steiner, Ann-Kristin,Amsharov, Konstantin Y.
supporting information, p. 14732 - 14736 (2017/10/23)
Intramolecular aryl–aryl coupling is the key transformation in the rational synthesis of nanographenes and nanoribbons. In this respect the C?F bond activation was shown to be a versatile alternative enabling the synthesis of several unique carbon-based nanostructures. Herein we describe an unprecedentedly challenging transformation showing that the C?F bond activation by aluminum oxide allows highly effective domino-like C?C bond formation. Despite the flexible nature of oligophenylene-based precursors efficient regioselective zipping to the target nanostructures was achieved. We show that fluorine positions in the precursor structure unambiguously dictate the “running of the zipping-program” which results in rolling-up of linear oligophenylene chains around phenyl moieties yielding target nanographenes. The high efficiency of zipping makes this approach attractive for the synthesis of unsubstituted nanographenes which are difficult to obtain in pure form by other methods.
