1034917-77-5Relevant articles and documents
A Twisted Nanographene Consisting of 96 Carbon Atoms
Cheung, Kwan Yin,Chan, Chi Kit,Liu, Zhifeng,Miao, Qian
, p. 9003 - 9007 (2017)
Herein we report synthesis, structure and properties of a new type of twisted nanographene, which contains an [8]circulene moiety in a polycyclic framework of 96 sp2 carbon atoms. The key steps in this synthesis are the Diels–Alder reaction of a macrocyclic diyne and the subsequent Scholl reaction forming the [8]circulene moiety. Two incompletely cyclized products were isolated from the Scholl reaction, providing insight into the cyclization of the strained octagon. This nanographene is twisted along two directions with end-to-end twists of 142.4° and 140.2° as revealed by X-ray crystallography, and is flexible at room temperature as found from the computational and experimental studies.
Rare-Earth Supported Nickel Catalysts for Alkyne Semihydrogenation: Chemo- And Regioselectivity Impacted by the Lewis Acidity and Size of the Support
Ramirez, Bianca L.,Lu, Connie C.
supporting information, p. 5396 - 5407 (2020/04/09)
Bimetallic catalysts of nickel(0) with a trivalent rare-earth ion or Ga(III), NiML3 (where L is [iPr2PCH2NPh]-, and M is Sc, Y, La, Lu, or Ga), were investigated for the selective hydrogenation of diphenylacetylene (DPA) to (E)-stilbene. Each bimetallic complex features a relatively short Ni-M bond length, ranging from 2.3395(8) ? (Ni-Ga) to 2.5732(4) ? (Ni-La). The anodic peak potentials of the NiML3 complexes vary from -0.48 V to -1.23 V, where the potentials are negatively correlated with the Lewis acidity of the M(III) ion. Three catalysts, Ni-Y, Ni-Lu, and Ni-Ga, showed nearly quantitative conversions in the semihydrogenation of DPA, with NiYL3 giving the highest selectivity for (E)-stilbene. Initial rate studies were performed on the two tandem catalytic reactions: DPA hydrogenation and (Z)-stilbene isomerization. The catalytic activity in DPA hydrogenation follows the order Ni-Ga > Ni-La > Ni-Y > Ni-Lu > Ni-Sc. The ranking of catalysts by (Z)-stilbene isomerization initial rates is Ni-Ga ? Ni-Sc > Ni-Lu > Ni-Y > Ni-La. In operando 31P and 1H NMR studies revealed that in the presence of DPA, the Ni bimetallic complexes supported by Y, Lu, and La form the Ni(η2-alkyne) intermediate, (η2-PhCCPh)Ni(iPr2PCH2NPh)2M(κ2-iPr2PCH2NPh). In contrast, the Ni-Ga resting state is the Ni(η2-H2) species, and Ni-Sc showed no detectable binding of either substrate. Hence, the mechanism of Ni-catalyzed diphenylacetylene semihydrogenation adheres to two different kinetics: an autotandem pathway (Ni-Ga, Ni-Sc) versus temporally separated tandem reactions (Ni-Y, Ni-Lu, Ni-La). Collectively, the experimental results demonstrate that modulating a base-metal center via a covalently appended Lewis acidic support is viable for promoting selective alkyne semihydrogenation.
Realizing n-Type Field-Effect Performance via Introducing Trifluoromethyl Groups into the Donor-Acceptor Copolymer Backbone
Wei, Congyuan,Zhang, Weifeng,Huang, Jianyao,Li, Hao,Zhou, Yankai,Yu, Gui
, p. 2911 - 2921 (2019/04/17)
Developing a new strategy to obtain n-type organic semiconductors is crucial for the advance of organic electronics. We herein report the synthesis and investigation of a series of donor-acceptor-type diazaisoindigo-based copolymers, named PAIID-TFBVB-C1,
Well-Defined Rhodium-Gallium Catalytic Sites in a Metal-Organic Framework: Promoter-Controlled Selectivity in Alkyne Semihydrogenation to E-Alkenes
Desai, Sai Puneet,Ye, Jingyun,Zheng, Jian,Ferrandon, Magali S.,Webber, Thomas E.,Platero-Prats, Ana E.,Duan, Jiaxin,Garcia-Holley, Paula,Camaioni, Donald M.,Chapman, Karena W.,Delferro, Massimiliano,Farha, Omar K.,Fulton, John L.,Gagliardi, Laura,Lercher, Johannes A.,Penn, R. Lee,Stein, Andreas,Lu, Connie C.
supporting information, p. 15309 - 15318 (2018/11/30)
Promoters are ubiquitous in industrial heterogeneous catalysts. The wider roles of promoters in accelerating catalysis and/or controlling selectivity are, however, not well understood. A model system has been developed where a heterobimetallic active site comprising an active metal (Rh) and a promoter ion (Ga) is preassembled and delivered onto a metal-organic framework (MOF) support, NU-1000. The Rh-Ga sites in NU-1000 selectively catalyze the hydrogenation of acyclic alkynes to E-alkenes. The overall stereoselectivity is complementary to the well-known Lindlar's catalyst, which generates Z-alkenes. The role of the Ga in promoting this unusual selectivity is evidenced by the lack of semihydrogenation selectivity when Ga is absent and only Rh is present in the active site.
Synthesis of Pinacolylboronate-Substituted Stilbenes and their application to the synthesis of boron capped polyenes
Das, Bhaskar C.,Mahalingam, Sakkarapalayam M.,Das, Sasmita,Hosmane, Narayan S.,Evans, Todd
supporting information, p. 51 - 59 (2015/12/18)
A series of novel 4,4,5,5-tetramethyl-2-(4-substitutedstyrylphenyl)-1,3,2 dioxaborolane derivatives has been synthesized. 4-(4,4,5,5-tetramethyl-1,3,2-dioxaboratophenyl)-methyl triphenylphosphonium bromide (4) was treated with 3 equiv of tBuONa, various a
Olefin cross-metathesis/Suzuki-Miyaura reactions on vinylphenylboronic acid pinacol esters
Baltus, Christine B.,Chuckowree, Irina S.,Press, Neil J.,Day, Iain J.,Coles, Simon J.,Tizzard, Graham J.,Spencer, John
, p. 1211 - 1217 (2013/03/13)
A series of alkenyl phenylboronic acid pinacol esters has been synthesized via an olefin cross-metathesis reaction of vinylphenylboronic acid pinacol ester derivatives. After catalytic hydrogenation, the resulting boronates were coupled via a microwave-mediated Suzuki-Miyaura reaction to afford a library of biarylethyl aryl and biarylethyl cycloalkyl derivatives. A complementary reaction sequence involved an initial Suzuki-Miyaura coupling.
ANTI-VIRAL COMPOUNDS
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Page/Page column 164-165, (2012/06/30)
Compounds effective in inhibiting replication of Hepatitis C virus ("HCV") are described. This invention also relates to processes of making such compounds, compositions comprising such compounds, and methods of using such compounds to treat HCV infection.
