56041-85-1Relevant academic research and scientific papers
Single-molecule conductance of dibenzopentalenes: antiaromaticity and quantum interference
Schmidt, Maximilian,Wassy, Daniel,Hermann, Mathias,González, M. Teresa,Agr?it, Nicolás,Zotti, Linda A.,Esser, Birgit,Leary, Edmund
, p. 745 - 748 (2021)
The effects of antiaromaticity and destructive quantum interference (DQI) are investigated on the charge transport through dibenzo-[a,e]pentalene (DBP). 5,10-Connectivity gives high single-molecule conductance whereas 2,7 gives low conductance due to DQI. Comparison of the 5,10-DBP with phenyl and anthracene analogues yields the trend GDBP ≈ GAnth > GPh, despite the aromatic anthracene having a larger HOMO-LUMO gap than 5,10-DBP. This is explained by unfavourable level alignment for 5,10-DBP. This journal is
Iron-Catalyzed Vinylzincation of Terminal Alkynes
Huang, Qiang,Su, Yu-Xuan,Sun, Wei,Hu, Meng-Yang,Wang, Wei-Na,Zhu, Shou-Fei
supporting information, p. 515 - 526 (2022/01/08)
Organozinc reagents are among the most commonly used organometallic reagents in modern synthetic chemistry, and multifunctionalized organozinc reagents can be synthesized from structurally simple, readily available ones by means of alkyne carbozincation. However, this method suffers from poor tolerance for terminal alkynes, and transformation of the newly introduced organic groups is difficult, which limits its applications. Herein, we report a method for vinylzincation of terminal alkynes catalyzed by newly developed iron catalysts bearing 1,10-phenanthroline-imine ligands. This method provides efficient access to novel organozinc reagents with a diverse array of structures and functional groups from readily available vinylzinc reagents and terminal alkynes. The method features excellent functional group tolerance (tolerated functional groups include amino, amide, cyano, ester, hydroxyl, sulfonyl, acetal, phosphono, pyridyl), a good substrate scope (suitable terminal alkynes include aryl, alkenyl, and alkyl acetylenes bearing various functional groups), and high chemoselectivity, regioselectivity, and stereoselectivity. The method could significantly improve the synthetic efficiency of various important bioactive molecules, including vitamin A. Mechanistic studies indicate that the new iron-1,10-phenanthroline-imine catalysts developed in this study have an extremely crowded reaction pocket, which promotes efficient transfer of the vinyl group to the alkynes, disfavors substitution reactions between the zinc reagent and the terminal C–H bond of the alkynes, and prevents the further reactions of the products. Our findings show that iron catalysts can be superior to other metal catalysts in terms of activity, chemoselectivity, regioselectivity, and stereoselectivity when suitable ligands are used.
Invisible Silver Guests Boost Order in a Framework That Cyclizes and Deposits Ag3Sb Nanodots
Ahn, Dohyun,Cheng, Shengxian,Feng, Weijin,He, Jun,Hu, Jieying,Xin, Yinger,Xu, Zhengtao,Zeller, Matthias
supporting information, p. 5757 - 5763 (2021/05/04)
The infusion of metal guests into (i.e., metalating) the porous medium of metal-organic frameworks (MOFs) is a topical approach to wide-ranging functionalization purposes. We report the notable interactions of AgSbF6 guests with the designer MOF host ZrL1 [Zr6O4(OH)7(L1)4.5(H2O)4]. (1) The heavy-atom guests of AgSbF6 induce order in the MOF host to allow the movable alkyne side arm to be fully located by X-ray diffraction, but they themselves curiously remain highly disordered and absent in the strucutral model. The enhanced order of the framework can be generally ascribed to interaction of the silver guests with the host alkyne and thioether functions, while the invisible heavy-atom guest represents a new phenomenon in the metalation of open framework materials. (2) The AgSbF6 guests also participate in the thermocyclization of the vicinal alkyne units of the L1 linker (at 450 °C) and form the rare nanoparticle of Ag3Sb supported on the concomitantly formed nanographene network. The resulted composite exhibits high electrical conductivity (1.0 S/cm) as well as useful, mitigated catalytic activity for selectively converting nitroarenes into the industrially important azo compounds, i.e., without overshooting to form the amine side products. The heterogeneous/cyclable catalysis entails only the cheap reducing reagents of NaBH4, ethanol, and water, with yields being generally close to 90%.
Linker Deficiency, Aromatic Ring Fusion, and Electrocatalysis in a Porous Ni8-Pyrazolate Network
Hu, Jieying,Deng, Xiangling,Zhang, Hu,Diao, Yingxue,Cheng, Shengxian,Zheng, Sai-Li,Liao, Wei-Ming,He, Jun,Xu, Zhengtao
supporting information, p. 161 - 166 (2021/01/11)
The cruciform linker molecule here features two designer functions: the pyrazole donors for framework construction, and the vicinal alkynyl units for benzannulation to form nanographene units into the Ni8-pyrazolate scaffold. Unlike the full 12 connections of the Ni8(OH)4(H2O)2 clusters in other Ni8-pyrazolate networks, significant linker deficiency was observed here, leaving about half of the Ni(II) sites capped by acetate ligands, which can be potentially removed to open the metal sites for reactivity. The crystalline Ni8-pyrazolate scaffold also retains the crystalline order even after thermal treatments (up to 300 °C) that served to partially graphitize the neighboring alkyne units. The resultant nanographene components enhance the electroactive properties of the porous hosts, achieving hydrogen evolution reaction (HER) activity that rivals that of topical nickel/palladium-enabled materials.
Photocatalyzed E→Z Contra-thermodynamic Isomerization of Vinyl Boronates with Binaphthol
Brégent, Thibaud,Bouillon, Jean-Philippe,Poisson, Thomas
supporting information, p. 13966 - 13970 (2021/08/25)
The photocatalytic contra-thermodynamic E→Z isomerization of vinyl boronates by using a binaphthol catalyst is disclosed. The reaction, based on the transient formation of a suitable chromophore with a BINOL derivative as the catalyst, allowed geometrical isomerization in good-to-excellent Z/E ratio and excellent-to-quantitative yields. The mechanism of this E→Z contra-thermodynamic isomerization was studied, and the formation of a transient chromophore species is suggested.
Synthesis, Electrochemistry, and Optical Properties of Highly Conjugated Alkynyl-Ferrocenes and -Biferrocenes
Bennett, Troy L. R.,Wilkinson, Luke A.,Lok, Jasmine M. A.,O'Toole, Robert C. P.,Long, Nicholas J.
, p. 1156 - 1162 (2021/05/06)
Sonogashira reactions are utilized herein to react iodo-ferrocenes and -biferrocenes with terminal alkyne ligands, functionalized with both pyridine and thioanisole groups. High-yielding reactions generate both monoalkynyl and dialkynyl derivatives, the r
1,2-Carbopentafluorophenylation of Alkynes: The Metallomimetic Pull-Push Reactivity of Tris(pentafluorophenyl)borane
Shibuya, Masatoshi,Matsuda, Miki,Yamamoto, Yoshihiko
supporting information, p. 8822 - 8831 (2021/05/21)
We report the novel single-step 1,2-dicarbofunctionalization of an arylacetylene with an allylsilane and tris(pentafluorophenyl)borane [B(C6F5)3] involving C?C bond formation with C?H bond scission at the β-position to the silicon atom of an allylsilane and B→C migration of a C6F5 group. The 1,2-carbopentafluorophenylation occurs smoothly without the requirement for a catalyst or heating. Mechanistic studies suggest that the metallomimetic “pull-push” reactivity of B(C6F5)3 imparts consecutive electrophilic and nucleophilic characteristics to the benzylic carbon of the arylacetylene. Subsequent photochemical 6π-electrocyclization affords tetrafluoronaphthalenes, which are important in the pharmaceutical and materials sciences. Owing to the unique reactivity of B(C6F5)3, the 1,2-carbopentafluorophenylation using 2-substituted furan proceeded with ring opening, and the reaction using silyl enolates formed a C?C bond with C?O bond scission at the silyloxy-substituted carbon.
Synthesis, Structure and Physical Properties of "wire-like" Metal Complexes
Naher, Masnun,Bock, S?ren,Langtry, Zakary M.,O'Malley, Kieran M.,Sobolev, Alexandre N.,Skelton, Brian W.,Korb, Marcus,Low, Paul J.
, p. 4667 - 4687 (2020/12/22)
The syntheses and crystallographically determined structures of metal complexes trans-[M(CCR)2Ln] (MLn = Ru(dppe)2, Ru{P(OEt)3}4, Pt(PEt3)2) featuring acetylide ligands further functionalized by aryl thioether groups are reported, together with those of a
Thermal decarboxylative Nazarov cyclization of cyclic enol carbonates involving chirality transfer
Kozuma, Akane,Komatsuki, Keiichi,Saito, Kodai,Yamada, Tohru
supporting information, p. 60 - 63 (2019/12/12)
Decarboxylative Nazarov cyclization of chiral cyclic enol carbonates proceeded to afford chiral 2-cyclopentenones with excellent chirality transfer under thermal conditions without any catalyst. Interestingly, the thermal decarboxylative Nazarov cyclization furnished the desired product with better chirality transfer than the Lewis acid-catalyzed reaction.
Symmetrically backfolded molecules emulating the self-similar features of a Sierpinski triangle
Hu, Jie-Ying,Sun, Yan-Qiong,Xiao, Ran,Cheng, Shengxian,He, Jun,Zeller, Matthias,Wong, Wai-Yeung,Xu, Zhengtao
supporting information, p. 6032 - 6037 (2019/06/24)
We synthesized self-similar molecules (G3 and G2; based on phenylalkynyl backbones) with symmetrically backfolded shapes inspired by the famous fractal of a Sierpinski triangle. Unlike the more traditional, starburst dendrimers, the centripetal-shaped Sierpinski molecules feature side branches symmetrically bent away from the growth direction of the main branch, thus contrasting the natural-tree shape. Molecule G3 exhibits three distinct levels of the structural hierarchy comprising the primary, secondary and tertiary branches, while the smaller G2 contains only features of the 1st and 2nd orders. In spite of the much larger conjugated backbone of G3, its solution UV-vis absorption and fluorescence exhibit no red shift relative to G2. In a test of nitrobenzene sensing, a thin film of G3 deposited from THF was more sensitively quenched in fluorescence than the smaller G2.
