- Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties
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A catalytic domino reduction–imine formation–intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, step-economical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.
- Hernández-Ruiz, Raquel,Rubio-Presa, Rubén,Suárez-Pantiga, Samuel,Pedrosa, María R.,Fernández-Rodríguez, Manuel A.,Tapia, M. José,Sanz, Roberto
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supporting information
p. 13613 - 13623
(2021/08/23)
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- An Accelerated Modular-Orthogonal Ni-Catalyzed Methodology to Symmetric and Nonsymmetric Constitutional Isomeric AB2to AB9Dendrons Exhibiting Unprecedented Self-Organizing Principles
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Five libraries of natural and synthetic phenolic acids containing five AB3, ten constitutional isomeric AB2, one AB4, and one AB5 were previously synthesized and reported by our laboratory in 5 to 11 steps. They were employed to construct seven libraries of self-assembling dendrons, by divergent generational, deconstruction, and combined approaches, enabling the discovery of a diversity of supramolecular assemblies including Frank-Kasper phases, soft quasicrystals, and complex helical organizations, some undergoing deracemization in the crystal state. However, higher substitution patterns within a single dendron were not accessible. Here we report three libraries consisting of 30 symmetric and nonsymmetric constitutional isomeric phenolic acids with unprecedented sequenced patterns, including two AB2, three AB3, eight AB4, five AB5, six AB6, three AB7, two AB8, and one AB9 synthesized by accelerated modular-orthogonal Ni-catalyzed borylation and cross-coupling. A single etherification step with 4-(n-dodecyloxy)benzyl chloride transformed all these phenolic acids, of interest also for other applications, into self-assembling dendrons. Despite this synthetic simplicity, they led to a diversity of unprecedented self-organizing principles: lamellar structures of interest for biological membrane mimics, helical columnar assemblies from rigid-solid angle dendrons forming Tobacco Mosaic Virus-like assemblies, columnar organizations from adaptable-solid angle dendrons forming disordered micellar-like nonhelical columns, columns from supramolecular spheres, five body-centered cubic phases displaying supramolecular orientational memory, rarely encountered in previous libraries forming predominantly Frank-Kasper phases, and two Frank-Kasper phases. Lessons from these self-organizing principles, discovered within a single generation of self-assembling dendrons, may help elaborate design principles for complex helical and nonhelical organizations of synthetic and biological matter.
- Daud, Hina,Hoffman, David J.,Huang, Ning,Jezorek, Ryan L.,Malineni, Jagadeesh,McClure, Emily R.,Partridge, Benjamin E.,Percec, Virgil,Peterca, Mihai,Sahoo, Dipankar,Song, Se Lin,Sung, Paul D.,Wang, Shitao,Wang, Xuefeng,Zhang, Na
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supporting information
p. 17724 - 17743
(2021/11/04)
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- Electrochemical Synthesis of Biaryls via Oxidative Intramolecular Coupling of Tetra(hetero)arylborates
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We report herein versatile, transition metal-free and additive-free (hetero)aryl-aryl coupling reactions promoted by the oxidative electrocoupling of unsymmetrical tetra(hetero)arylborates (TABs) prepared from ligand-exchange reactions on potassium trifluoroarylborates. Exploiting the power of electrochemical oxidations, this method complements the existing organoboron toolbox. We demonstrate the broad scope, scalability, and robustness of this unconventional catalyst-free transformation, leading to functionalized biaryls and ultimately furnishing drug-like small molecules, as well as late stage derivatization of natural compounds. In addition, the observed selectivity of the oxidative coupling reaction is related to the electronic structure of the TABs through quantum-chemical calculations and experimental investigations.
- Music, Arif,Baumann, Andreas N.,Spie?, Philipp,Plantefol, Allan,Jagau, Thomas C.,Didier, Dorian
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supporting information
p. 4341 - 4348
(2020/03/04)
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- Novel syntheses of fluorenones via nitrile-directed palladium-catalyzed C-H and dual C-H bond activation
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Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
- Wan, Jung-Chih,Huang, Jun-Min,Jhan, Yu-Huei,Hsieh, Jen-Chieh
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supporting information
p. 2742 - 2745
(2013/07/19)
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- Introduction of allyi and prenyl side-chains into aromatic systems by suzuki cross-coupling reactions
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This paper reports some studies aiming at the developement of a general protocol useful for the synthesis of allyl- and prenylaromatic compounds. The first part deals with, the preparation of boron reagents like arylboronic acids and their pinacol esters as well as of pinacol allyl- and prenylboronates. The second part of the paper is devoted to the use of these boron reagents in Suzuki-Miyaura cross-coupling reactions leading to allylation and prenylation of aromatic compounds. Of the six methods studied, the most promising re-suits were obtained by using the Pd2(dba)3-catalyzed reactions of arylboronic acids with allyl and prenyl bromides, that lead to the products of cross coupling in high yields (average 87%), and the reactions of aryl trifluoroborates with allyl and prenyl bromides catalyzed by Pd(OAc)2 that lead to the products of coupling in all cases in high yields (average 82%).
- Gerbino, Dario C.,Mandolesi, Sandra D.,Schmalz, Hans-Guenther,Podesta, Julio C.
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scheme or table
p. 3964 - 3972
(2010/02/27)
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- Predicting the structure of supramolecular dendrimers via the analysis of libraries of AB3 and constitutional isomeric AB2 biphenylpropyl ether self-assembling dendrons
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The synthesis of 4′-hydroxy-4-biphenylpropionic, 3′,4′- dihydroxy-4-biphenylpropionic, 3′,5′-dihydroxy-4-biphenylpropionic, and 3′,4′,5′-trihydroxy-4-biphenylpropionic methyl esters via three efficient and modular strategies including one based on Ni-catalyzed borylation and sequential cross-coupling is reported. These building blocks were employed in a convergent iterative approach to the synthesis of one library of 3,4,5-trisubstituted and two libraries of constitutional isomeric 3,4- and 3,5-disubstituted biphenylpropyl ether dendrons. Structural and retrostructural analysis of supramolecular dendrimers revealed that biphenylpropyl ether dendrons self-assemble and self-organize into the same periodic lattices and quasi-periodic arrays observed in previously reported libraries, but with larger dimensions, different mechanisms of self-assembly, and improved solubility, thermal, acidic, and oxidative stability. The different mechanisms of self-assembly led to the discovery of two new supramolecular structures. The first represents a new banana-like lamellar crystal with a four layer repeat. The second is a giant vesicular sphere self-assembled from 770 dendrons that exhibits an ultrahigh molar mass of 1.73 × 106 g/mol. Thus, the enhanced size of the self-assembled structures constructed from biphenylpropyl ether dendrons permitted for the first time discrimination of various molecular mechanisms of spherical self-assembly and elaborated a continuum between small filled spheres and very large hollow spheres that is dictated by the primary structure of the dendron. The comparative analysis of libraries of biphenylpropyl ether dendrons with the previously reported libraries of benzyl-, phenylpropyl-, and biphenyl-4-methyl ether dendrons demonstrated biomimetic self-assembly wherein the primary structure of the dendron and to a lesser extent the structure of its repeat unit determines the supramolecular tertiary structure. A "nanoperiodic table" of self-assembling dendrons and supramolecular dendrimers that allows the prediction of the general features of tertiary structures from primary structures was elaborated.
- Rosen, Brad M.,Wilson, Daniela A.,Wilson, Christopher J.,Peterca, Mihai,Won, Betty C.,Huang, Chenghong,Lipski, Linda R.,Zeng, Xiangbing,Ungar, Goran,Heiney, Paul A.,Percec, Virgil
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supporting information; experimental part
p. 17500 - 17521
(2010/03/25)
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- Palladium-catalyzed cross-coupling of N-benzenesulfonyl-3,4-dibromopyrrole and its application to the total syntheses of lamellarins O, P, Q, and R
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Palladium-catalyzed Suzuki-Miyaura coupling of N-benzenesulfonyl-3,4-dibromopyrrole with a variety of arylboronic acids gave the corresponding 3,4-diarylpyrroles in high yields. The 3,4-differentially arylated pyrroles could also be prepared by stepwise cross-coupling approach. The total syntheses of lamellarins O, P, Q, and R have been achieved by using the cross-coupling and the directed lithiation as key reactions.
- Fukuda, Tsutomu,Sudo, Ei-ichi,Shimokawa, Kozue,Iwao, Masatomo
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p. 328 - 338
(2008/04/01)
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- Formation of hetero-boroxines: Dynamic combinatorial libraries generated through trimerization of pairs of arylboronic acids
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Condensation of pairs of arylboronic acids provided homo- and hetero-boroxines in solution as evidenced from NMR spectra, and those boroxines were detected in the gas phase by GC-MS spectrometry. Equilibrium constants for the formation of these boroxines in solution were obtained through integration of pertinent signals in the NMR spectra of the mixtures ofboronic acids.
- Tokunaga, Yuji,Ueno, Hiroki,Shimomura, Youji
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p. 219 - 223
(2008/09/17)
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- Methodology for the synthesis of 1,2-disubstituted arylnaphthalenes from α-tetralones
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α-Tetralones were initially converted into 1-bromo- dihydronaphthalene-2-carbaldehydes and 1-bromo-naphthalene-2-carbaldehydes. These precursors were then subjected to Suzuki coupling reactions to afford 1,2-disubstituted aryldihydronaphthalenes and 1,2-disubstituted arylnaphthalenes, respectively. The former products were oxidized with DDQ to give 1,2-disubstituted arylnaphthalenes.
- Moleele, Simon S.,Michael, Joseph P.,De Koning, Charles B.
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p. 2831 - 2844
(2007/10/03)
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- Short and flexible route to 3,4-diarylpyrrole marine alkaloids: Syntheses of permethyl storniamide A, ningalin B, and lamellarin G trimethyl ether
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A highly efficient route to 3,4-diarylpyrrole marine alkaloids has been developed using Hinsberg-type pyrrole synthesis and palladium-catalyzed Suzuki cross-coupling of the 3,4-dihydroxypyrrole bis-triflate derivatives as key reactions. Based on this approach, formal syntheses of permethyl storniamide A and ningalin B, and a total synthesis of lamellarin G trimethyl ether have been achieved.
- Iwao, Masatomo,Takeuchi, Toshiro,Fujikawa, Naotaka,Fukuda, Tsutomu,Ishibashi, Fumito
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p. 4443 - 4446
(2007/10/03)
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- Tetraphenylethene-derived columnar liquid crystals and their oxidative photocyclization
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The synthesis of novel tetraphenylethenes 9a-f, 13, and 18a,b bearing ether, biphenyl, and 4-cyanobiphenyl moieties via a McMurry reaction and Suzuki coupling as key steps is described. Mesogenic properties of these compounds were studied by differential
- Schultz, Andreas,Laschat, Sabine,Diele, Siegmar,Nimtz, Manfred
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p. 2829 - 2839
(2007/10/03)
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