Synthesis of Hydroxy‐Substituted <i>p</i>‐Terphenyls and some Larger Oligophenylenes <i>via</i> Palladium on Charcoal Catalyzed Suzuki‐Miyaura Reaction

Jansa, Josef; Řezníček, Tomáš; Jambor, Roman; Bureš, Filip; Lyčka, Antonı́n

doi:10.1002/adsc.201600487

Cited by 10 publications

(7 citation statements)

References 66 publications

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“…In preliminary experiments, we were able to demonstrate that in flow format, phosphine ligand-free Suzuki reactions could be carried out with low catalyst loadings using palladium acetate as catalyst and water as cosolvent. Under these conditions, rapid coupling reactions were observed and phosphine-related side reactions such as aryl-aryl exchange eliminated, avoiding constraints reported for batch synthesis (34)(35)(36)(37)(38)(39). Adaptation of similar flow chemical procedures to double coupling of 1,4-dibromo-2-nitrobenzene (1) using ethanol as a co-solvent led to further improvements in regio-selectivity and higher yields compared to the corresponding one-pot double Suzuki couplings carried out in the batch mode.…”

Section: Resultsmentioning

confidence: 99%

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Kazi

Campi

Hearn

2019

Green Chemistry Letters and Reviews

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Synthetic procedures, based on integrated flow chemical methods, have been developed for the sequential chemo-selective Suzuki-Miyaura cross-coupling of 1,4-dibromo-2-nitrobenzene (1) with various arylboronic acids. The first Suzuki coupling step used a phosphine-(ligand)-free palladium catalyst at room temperature and gave regio-selective coupling of (1) at the orthoposition to the nitro group. The bromo-biaryl product was then directly subjected in situ to a second coupling step, using different arylboronic acids, as a continuous in-flow operation. Based on this methodology, a number of unsymmetrically substituted p-terphenyl compounds were synthesized in excellent overall yields. This approach provides a convenient route to this class of compounds, and is suited for the generation of targeted chemical libraries, or the synthesis of precursors of biologically active natural product analogues that contain the p-terphenyl core. During the first coupling step, dimerization at low levels of the bromo-biaryl intermediate occurred, leading to formation of quaterphenyl compounds.

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Section: Resultsmentioning

confidence: 99%

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Kazi

Campi

Hearn

2019

Green Chemistry Letters and Reviews

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“…The synthesis of target imidazopyrimidines 3a‐z was adopted from our previous paper . Firstly, iododerivative 2 was prepared by the reaction of 5‐iodocytosine 1 with chloroacetaldehyde.…”

Section: Resultsmentioning

confidence: 99%

Imidazo[1,2‐c]pyrimidin‐5(6H)‐one as a novel core of cyclin‐dependent kinase 2 inhibitors: Synthesis, activity measurement, docking, and quantum mechanical scoring

Ajani

Jansa

Köprülüoğlu

et al. 2018

J of Molecular Recognition

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We report on the synthesis, activity testing, docking, and quantum mechanical scoring of novel imidazo[1,2-c]pyrimidin-5(6H)-one scaffold for cyclin-dependent kinase 2 (CDK2) inhibition. A series of 26 compounds substituted with aromatic moieties at position 8 has been tested in in vitro enzyme assays and shown to inhibit CDK2. 2D structure-activity relationships have ascertained that small substituents at position 8 (up to the size of naphtyl or methoxyphenyl) generally lead to single-digit micromolar IC values, whereas bigger substituents (substituted biphenyls) decreased the compounds' activities. The binding modes of the compounds obtained using Glide docking have exhibited up to 2 hinge-region hydrogen bonds to CDK2 and differed in the orientation of the inhibitor core and the placement of the 8-substituents. Semiempirical quantum mechanics-based scoring identified probable favourable binding modes, which will serve for future structure-based design and synthetic optimization of substituents of the heterocyclic core. In summary, we have identified a novel core for CDK2 inhibition and will explore it further to increase the potencies of the compounds and also monitor selectivities against other protein kinases.

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“…CÀCb ondf ormation is one of the most important processes in synthetic organic chemistry.T he most common and wellknown types are Suzuki, [1][2][3] Heck, [4,5] and Sonogashira coupling reactions, [6] and so on. These provide facile and highly efficient routes for the synthesis of natural products, polymers, [7,8] agrochemicals, and pharmaceuticals.…”

Section: Introductionmentioning

confidence: 99%

Support‐Free Pd₃Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C−C Coupling Reactions

Pradhan

Mishra

Lee

2019

Chemistry A European J

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A support‐free heterogeneous Pd3Co nanostructured composite (NC), synthesized through a hydrothermal route, acted as an effective catalytic system in multivariate Heck‐, Sonogashira‐, and Suzuki‐type coupling reactions of iodonium ylides. The XPS analysis of the bimetallic Pd3Co NCs confirmed the elemental composition as 75 % palladium and 25 % cobalt. Furthermore, high‐resolution (HR) TEM analysis confirmed the spherical morphology of the Pd3Co bimetallic nanoparticles. The average diameter of the NCs is 14.8 nm. The coupling reaction proceeded through the generation of α‐iodoenones with simultaneous migration of the phenyl group, thereby giving a scaffold with higher atom economy. The heterogeneous Pd3Co NCs were recycled and reused without any significant change in catalytic ability for up to five reaction cycles. The high concentration of Pd and association of cobalt into the lattice of palladium appears to enhance its catalytic ability for the diverse coupling reactions in comparison with its monometallic counterparts as well as with bimetallic NCs with a comparatively lesser amount of Pd.

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Synthesis of Hydroxy‐Substituted p‐Terphenyls and some Larger Oligophenylenes via Palladium on Charcoal Catalyzed Suzuki‐Miyaura Reaction

Cited by 10 publications

References 66 publications

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Imidazo[1,2‐c]pyrimidin‐5(6H)‐one as a novel core of cyclin‐dependent kinase 2 inhibitors: Synthesis, activity measurement, docking, and quantum mechanical scoring

Support‐Free Pd₃Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C−C Coupling Reactions

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Synthesis of Hydroxy‐Substituted p‐Terphenyls and some Larger Oligophenylenes via Palladium on Charcoal Catalyzed Suzuki‐Miyaura Reaction

Cited by 10 publications

References 66 publications

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Flow reactor synthesis of unsymmetrically substitutedp-terphenyls using sequentially selective Suzuki cross-coupling protocols

Imidazo[1,2‐c]pyrimidin‐5(6H)‐one as a novel core of cyclin‐dependent kinase 2 inhibitors: Synthesis, activity measurement, docking, and quantum mechanical scoring

Support‐Free Pd3Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C−C Coupling Reactions

Contact Info

Product

Resources

About

Support‐Free Pd₃Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C−C Coupling Reactions