330793-01-6Relevant articles and documents
Cooperative Self-Assembly of Pyridine-2,6-Diimine-Linked Macrocycles into Mechanically Robust Nanotubes
Strauss, Michael J.,Asheghali, Darya,Evans, Austin M.,Li, Rebecca L.,Chavez, Anton D.,Sun, Chao,Becker, Matthew L.,Dichtel, William R.
, p. 14708 - 14714 (2019)
Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length and mechanical
Photo-induced thiolate catalytic activation of inert Caryl-hetero bonds for radical borylation
K?nig, Burkhard,Wang, Hua,Wang, Shun
, p. 1653 - 1665 (2021/06/17)
Substantial effort is currently being devoted to obtaining photoredox catalysts with high redox power. Yet, it remains challenging to apply the currently established methods to the activation of bonds with high bond dissociation energy and to substrates with high reduction potentials. Herein, we introduce a novel photocatalytic strategy for the activation of inert substituted arenes for aryl borylation by using thiolate as a catalyst. This catalytic system exhibits strong reducing ability and engages non-activated Caryl–F, Caryl–X, Caryl–O, Caryl–N, and Caryl–S bonds in productive radical borylation reactions, thus expanding the available aryl radical precursor scope. Despite its high reducing power, the method has a broad substrate scope and good functional-group tolerance. Spectroscopic investigations and control experiments suggest the formation of a charge-transfer complex as the key step to activate the substrates.
Diverse Proton-Conducting Nanotubes via a Tandem Macrocyclization and Assembly Strategy
Strauss, Michael J.,Jia, Manping,Evans, Austin M.,Castano, Ioannina,Li, Rebecca L.,Aguilar-Enriquez, Xavier,Roesner, Emily K.,Swartz, Jeremy L.,Chavez, Anton D.,Enciso, Alan E.,Stoddart, J. Fraser,Rolandi, Marco,Dichtel, William R.
supporting information, p. 8145 - 8153 (2021/06/21)
Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. We report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6-triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5 + 5], hexagonal [3 + 3], and diamond-shaped [2 + 2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer. Atomic force microscopy and in solvo X-ray diffraction demonstrate that protonation of the macrocycles under the mild conditions used for their synthesis drives assembly into high-aspect ratio nanotubes. Each of the pyridine-containing nanotube assemblies exhibited measurable proton conductivity by electrochemical impedance spectroscopy, with values as high as 10-3 S m-1 (90% R.H., 25 °C) that we attribute to differences in their internal pore sizes. This synthetic strategy represents a general method to access robust nanotube assemblies from a universal pyridine-containing monomer, which will enable systematic investigations of their emergent properties.
Non-innocent Radical Ion Intermediates in Photoredox Catalysis: Parallel Reduction Modes Enable Coupling of Diverse Aryl Chlorides
Chernowsky, Colleen P.,Chmiel, Alyah F.,Wickens, Zachary K.,Williams, Oliver P.,Yeung, Charles S.
supporting information, p. 10882 - 10889 (2021/07/31)
We describe a photocatalytic system that elicits potent photoreductant activity from conventional photocatalysts by leveraging radical anion intermediates generated in situ. The combination of an isophthalonitrile photocatalyst and sodium formate promotes diverse aryl radical coupling reactions from abundant but difficult to reduce aryl chloride substrates. Mechanistic studies reveal two parallel pathways for substrate reduction both enabled by a key terminal reductant byproduct, carbon dioxide radical anion.
Visible Light-Induced Borylation of C-O, C-N, and C-X Bonds
Arman, Hadi D.,Dang, Hang. T.,Haug, Graham C.,He, Ru,Jin, Shengfei,Larionov, Oleg V.,Nguyen, Viet D.,Nguyen, Vu T.,Schanze, Kirk S.
, (2020/02/04)
Boronic acids are centrally important functional motifs and synthetic precursors. Visible light-induced borylation may provide access to structurally diverse boronates, but a broadly efficient photocatalytic borylation method that can effect borylation of a wide range of substrates, including strong C-O bonds, remains elusive. Herein, we report a general, metal-free visible light-induced photocatalytic borylation platform that enables borylation of electron-rich derivatives of phenols and anilines, chloroarenes, as well as other haloarenes. The reaction exhibits excellent functional group tolerance, as demonstrated by the borylation of a range of structurally complex substrates. Remarkably, the reaction is catalyzed by phenothiazine, a simple organic photocatalyst with MW 200 that mediates the previously unachievable visible light-induced single electron reduction of phenol derivatives with reduction potentials as negative as approximately - 3 V versus SCE by a proton-coupled electron transfer mechanism. Mechanistic studies point to the crucial role of the photocatalyst-base interaction.
Purine compound obtained based on virtual docking as well as preparation method and application of same
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Paragraph 0035-0042, (2020/11/26)
The invention provides a purine compound obtained based on virtual docking. The purine compound is screened in a virtual screening and pharmacophore manner, through a result of mutual evidence verification of virtual docking design and compound synthesis,
Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials
Kim, Hyunwoo,Kim, Hyungjun,Lambert, Tristan H.,Lin, Song
supporting information, p. 2087 - 2092 (2020/02/04)
We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of -3.2 V vs SCE, which can be used to activate substrates with very high reduction potentials (Ered ≈ -1.9 to -2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.
Copper-Photocatalyzed Borylation of Organic Halides under Batch and Continuous-Flow Conditions
Nitelet, Antoine,Thevenet, Damien,Schiavi, Bruno,Hardouin, Christophe,Fournier, Jean,Tamion, Rodolphe,Pannecoucke, Xavier,Jubault, Philippe,Poisson, Thomas
supporting information, p. 3262 - 3266 (2019/02/13)
The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested.
Hydrogenation of (Hetero)aryl Boronate Esters with a Cyclic (Alkyl)(amino)carbene–Rhodium Complex: Direct Access to cis-Substituted Borylated Cycloalkanes and Saturated Heterocycles
Ling, Liang,He, Yuan,Zhang, Xue,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 6554 - 6558 (2019/04/17)
We herein report the hydrogenation of substituted aryl- and heteroaryl boronate esters for the selective synthesis of cis-substituted borylated cycloalkanes and saturated heterocycles. A cyclic (alkyl)(amino)carbene-ligated rhodium complex with two dimethyl groups at the ortho-alkyl scaffold of the carbene showed high reactivity in promoting the hydrogenation, thereby enabling the hydrogenation of (hetero)arenes with retention of the synthetically valuable boronate group. This process constitutes a clean, atom-economic, as well as chemo- and stereoselective route for the generation of cis-configured, diversely substituted borylated cycloalkanes and saturated heterocycles that are usually elusive and difficult to prepare.
Equilibration of Imine-Linked Polymers to Hexagonal Macrocycles Driven by Self-Assembly
Chavez, Anton D.,Evans, Austin M.,Flanders, Nathan C.,Bisbey, Ryan P.,Vitaku, Edon,Chen, Lin X.,Dichtel, William R.
supporting information, p. 3989 - 3993 (2018/03/01)
Macrocycles based on directional bonding and dynamic covalent bond exchange can be designed with specific pore shapes, sizes, and functionality. These systems retain many of the design criteria and desirable aspects of two-dimensional (2D) covalent organi
