[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• , alkyl or alkenyl group via Suzuki coupling reaction with boronic acids to give otherwise rarely available 1,4,5-trisubstituted pyrazoles [119]. The second limitation is that the CuSAC reaction proceeds only with terminal alkynes. The latter fact clearly indicates some kind of participation of the

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• for the stability of 37 and to facilitate functional group interconversions as shown in Figure 12A [53]. In order to obtain carbocyclic C-nucleosides that resemble canonical nucleosides, Maier and coworkers synthesized a stable enol triflate (46, Figure 13A), which then enables Suzuki coupling and a

• modular synthesis of carbocyclic C-nucleosides [53]. The boronic acids/boronates (inset, Figure 13) of several (hetero)aryls were conducive to Suzuki coupling with the best result obtained when the C2', C3' and C5'–OHs were protected with TIPS and pivaloyl groups, respectively [53]. The cross-coupling

• separable mixture of diastereomers (2:1). In addition, optically pure cyclopentanone (−)-45 was obtained by converting the cyclopentane 43 to camphanates (51, Figure 13B) followed by separation of the diastereomers [53]. Subsequent synthesis of the enol triflate (−)-46 (Figure 13B), Suzuki coupling and

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• nanoparticles (DSN) have been shown to be highly efficient in the catalysis of olefin hydrogenation and in Suzuki coupling reactions [98][99]. Ornelas et al. entrapped a palladium catalyst with dendrimers containing triazole groups (DSN) (Figure 6) [100]. The aim here was to provide a platform to perform

• hydrogenation in water. By using only 0.01% of palladium at room temperature, the hydrogenation of allyl alcohol was realized [101]. DSNs were recycled for up to 10 times without loss in activity. DSN nanoreactors were later shown to be utilized for catalysing Suzuki coupling reactions between PhB(OH)2 and PhX

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• corresponding N1-alkyl-3-iodopyrazolo[3,4-d]pyrimidine derivatives 225. The iodinated pyrazolo[3,4-d]pyrimidines were alkylated at C3 with boronic acids (R2-B(OH)2) using Suzuki coupling conditions to give 4-amino-N1,C3-dialkylpyrazolo[3,4-d]pyrimidines 226 (Scheme 61). Synthesis of pyrazolo[3,4-b]pyrazines

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• first construct a common intermediate that could be used for various Suzuki-coupling partners similar to what we previously reported [55], by first protecting 6-chloro-7-iodo-7-deazapurine with tert-butyldimethylsilyloxymethyl (TBDMSOM) in 86% yield over two steps (44, Scheme 10). A Miyaura-type

• borylation afforded the common intermediate 45 in 91% yield and Suzuki coupling was then achieved efficiently for both 2-amino-3-iodopyridine as well as 2-iodo-4-nitroaniline in (46) 95% and (47) 86% yield, respectively. The activation of the exocyclic amine was achieved by using AcCl which provided a more

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• . Furthermore, the same structural dimer of TFEO-Pc and tert-butyl-substituted phthalocyanine 7b was synthesized by the Suzuki coupling reaction. These dimers show a new absorption peak in the longer wavelength region than the Q band which is not observed in the monomer. This suggests intramolecular electronic

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• -free Wittig reaction of organic halides with aldehydes or ketones (Scheme 6) [55]. Suzuki Coupling In 2000, Peters and co-workers first reported the palladium-catalyzed Suzuki coupling reaction under ball-milling conditions [56]. In a planetary mill for 30–60 min, the mixture of aryl halide (1.0 equiv

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Synthesis of the heterocyclic core of the D-series GE2270

• Christophe Berini,
• Thibaut Martin,
• Pierrik Lassalas,
• Francis Marsais,
• Christine Baudequin and
• Christophe Hoarau

Beilstein J. Org. Chem. 2017, 13, 1407–1412, doi:10.3762/bjoc.13.137

• by using two developed innovative cross-coupling reactions, the palladium-catalyzed direct C–H (hetero)arylation of thiazole-4-carboxylate [21] and a palladium-catalyzed borylation-Suzuki coupling (BSC) 2-ketothiazole unit at 4-position as alternative to thiazolyltin intermediate [22]. Herein, an

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• -propanediol)ester under Suzuki coupling reaction conditions in the presence of sodium bicarbonate solution with tris(dibenzylideneacetone)dipalladium(0) and tri-o-tolylphosphine as the catalyst (Scheme 2). For experimental details, see Supporting Information File 1. The crude polymers were precipitated with

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• /PANI catalyzed a Suzuki coupling reaction and hydroxylation of aryl halides [25]. The hydroxylation of aryl halides occurred at 100 °C in aqueous 1,4-dioxane in the presence of 1 mol % of Pd/PANI and 4 equiv of KOH (Scheme 5). Aryl bromide and iodides were converted to the corresponding phenols in good

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• phenyl group was proposed to introduce at the 3-position in substituted pyrazinone via regioselective bromination followed by Suzuki coupling with phenylboronic acid. Accordingly, the bromination of 10a was successfully carried out to furnish regioisomers 12a and 12b in 82% yield upon treatment with

• bromodimethylsulfonium bromide (BDMS) [38] in dichloromethane at 0 °C to room temperature. The conventional Suzuki coupling of the regioisomers 12a and 12b with phenylboronic acid furnished the corresponding arylated products 13a and 13b in excellent yield (Scheme 5). To our dismay, the imide 7h did not participate in

Highly bulky and stable geometry-constrained iminopyridines: Synthesis, structure and application in Pd-catalyzed Suzuki coupling of aryl chlorides

• Yi Lai,
• Zhijian Zong,
• Yujie Tang,
• Weimin Mo,
• Nan Sun,
• Baoxiang Hu,
• Zhenlu Shen,
• Liqun Jin,
• Wen-hua Sun and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 213–221, doi:10.3762/bjoc.13.24

• without any change except at the higher reaction temperature. As shown in Table 1, using complex Pd1, which has exhibited an impressive efficiency in Pd-catalyzed Suzuki coupling of aryl bromides, only delivered 18% conversion of chlorobenzene. The modification of the Cb position by importing two methyl

• been proven to play an important role in Suzuki coupling reactions [74]. Then, in mixed solvents, various bases were examined (Table 3, entries 1–10). Compared with K2CO3, the other tested bases did not show any advantage. Increasing the amount of base to 2.5 equivalents or elevating the temperature to

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• -forming reactions such as Sonogashira, Heck, or Suzuki coupling reactions as well as a cyanation reaction. These cross-coupling reactions led to a series of 5-alkynyl-, 5-alkenyl-, 5-aryl- and 5-cyano-substituted 1,2-oxazine derivatives being of considerable interest for further synthetic elaborations

Symmetry-based approach to oligostilbenoids: Rapid entry to viniferifuran, shoreaphenol, malibatol A, and diptoindonesin G

• Youngeun Jung,
• Dileep Kumar Singh and
• Ikyon Kim

Beilstein J. Org. Chem. 2016, 12, 2689–2693, doi:10.3762/bjoc.12.266

• natural oligostilbenoids guided us to design a modular synthetic approach to these molecules by utilizing a three-step sequence consisting of Sonogashira coupling, iodocyclization, and Suzuki coupling. During our synthesis, the relative reactivities of ester, aldehyde, and alkoxy groups on the same aryl

• element [19] of the target molecules. We expected that the key intermediate (inset box of Scheme 1) could be constructed from the monoiodo compounds 1, 2, or 3 through a sequence involving Sonogashira coupling, iodocyclization [20][21][22][23][24][25][26], and Suzuki coupling. As the starting materials (1

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• for mechanochemical syntheses include stoichiometric reactions such as the Knoevenagel condensation and the Wittig reaction, but also reactions catalyzed by metal catalysts, like the Sonogashira coupling and the Suzuki coupling [1]. Photocatalysis, as a part of Ostwald’s sub-discipline photochemistry

Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

• Arne Klinkebiel,
• Ole Beyer,
• Barbara Malawko and
• Ulrich Lüning

Beilstein J. Org. Chem. 2016, 12, 2267–2273, doi:10.3762/bjoc.12.219

• substituted) with two equivalents of an unsubstituted nitrile. Triple Suzuki coupling of the cores 3 with suitable phenyl- and biphenylboronic acid derivatives provided elongated tricarboxylic acid linkers as carboxylic acids 17 and 20 or their esters 16 and 19. Reduction of the nitro group and cleavage of

• the methoxy group gave the respective amino and hydroxy-substituted triazine linkers. Keywords: isoreticular; linker; MOF; Suzuki coupling; triazine; Introduction A typical building block for many metal–organic frameworks (MOFs) [1][2][3][4] carries two functional groups such as carboxylic acids or

• because each of the reactions had to be performed three times with each triazine. Thus the total yield of the final product depends on the yield of the single step to the power of three. In a triple Suzuki coupling, 4-(methoxycarbonyl)phenylboronic acid (15) as the coupling partner yielded elongated and

Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group

• Mariem Brahim,
• Hamed Ben Ammar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2016, 12, 2197–2203, doi:10.3762/bjoc.12.210

• , without cleavage of the thienyl C–Br bond. Moreover, sequential direct thienyl C5-arylation followed by Pd-catalysed direct arylation or Suzuki coupling at the C2-position allows to prepare 2,5-di(hetero)arylated thiophenes bearing two different (hetero)aryl units in only two steps. This method provides a

• -substituted thiophenes derivatives containing two different aryl groups at C2 and C5 positions via Suzuki coupling in the second step was also attempted (Scheme 8). The reaction of 5 with phenylboronic acid in the presence of only 1 mol % Pd(OAc)2 catalyst and K2CO3 as base gave 3-methyl-5-(4-nitrophenyl)-2

• (hetero)aryl bromides. The sequential direct C5-arylation of 2-bromothiophenes followed either by a Suzuki coupling or a second direct arylation was found to allow the preparation of 2,5-di(hetero)arylated thiophenes bearing two different (hetero)aryl units. This method provides a convenient “greener

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• characterization by electronic spectroscopy, cyclic voltammetry, and quantum chemical computations. Results and Discussion Synthesis of thienyl-bridged oligophenothiazines Although the thienyl bridge can be introduced by Suzuki coupling as previously reported [48], we decided to transpose a methodology initiated

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• selectivity for the DHQ over the corresponding THQ. Comparison of the reactivity of 6-iodo-THQ 21 and 6-bromo-THQ 26 in a typical Suzuki coupling reaction showed significantly improved conversion in the case of the iodide. The resulting biaryl 28 was found to be highly fluorescent, highlighting the

Effect of the π-conjugation length on the properties and photovoltaic performance of A–π–D–π–A type oligothiophenes with a 4,8-bis(thienyl)benzo[1,2-b:4,5-b′]dithiophene core

• Ni Yin,
• Lilei Wang,
• Yi Lin,
• Jinduo Yi,
• Lingpeng Yan,
• Junyan Dou,
• Hai-Bo Yang,
• Xin Zhao and
• Chang-Qi Ma

Beilstein J. Org. Chem. 2016, 12, 1788–1797, doi:10.3762/bjoc.12.169

• ), TBDT = 4,8-bis(5-alkyl-2-thienyl)benzo[1,2-b:4,5-b′]dithiophene) is shown in Scheme 1. The bithiophene building block, 3,4'-dihexyl-5'-iodo-2,2'-bithiophene-5-carbaldehyde (11) was synthesized by an ipso-substitution of 10, which was synthesized by a Suzuki coupling of 9 with 6, with ICl. The

Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations

• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1170–1177, doi:10.3762/bjoc.12.112

• prepared by the methods described above are excellent and versatile precursors for transition-metal-catalyzed coupling reactions [32][53][54][55][56][57]. Standard conditions for a Suzuki coupling smoothly transform compound 5a and a boronic acid derivative into the expected 4-tolyl-substituted derivative

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• conditions with a desired primary alcohol. One such alcohol, 2-cyclopropylprop-2-en-1-ol, can be synthesized using a modified Suzuki coupling procedure developed by Soderquist [49] (Scheme 5b). A cyclopropyl boronate can be generated from propargyl bromide, 9-BBN, and aqueous sodium hydroxide. This reactive

• for chiral sulfoxide synthesis. (a) General synthetic sequence to access enyne bicycloisomerization substrates (b) Synthesis of 2-cyclopropylprop-2-en-1-ol using a modified Suzuki coupling reaction developed by Soderquist. Deprotection of [3.1.0] bicycles and X-ray crystal structure of 76. ProPhenol

The role of alkyl substituents in deazaadenine-based diarylethene photoswitches

• Christopher Sarter,
• Michael Heimes and
• Andres Jäschke

Beilstein J. Org. Chem. 2016, 12, 1103–1110, doi:10.3762/bjoc.12.106

• benzenesulfonyl chloride, resulting in a four-fold increased yield of 6 compared to the original route. The other part of the diarylethene, namely the cyclopentenyl bridge with the attached substituted thiophene ring was furnished as shown in Scheme 3 and activated as boronic acid pinacolate ester. Suzuki

• coupling yielded the eight target compounds in yields between 36% and 97%. Two of these compounds (2b,c) are identical to the ones reported previously [43], while the other 6 represent new compounds. Photophysical and photochemical characterization For diarylethenes 1a–d and 2a–d, the photophysical and

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• γCD [43][44][45], or TMS-γCD [46]. Therefore, 3·TM-βCD and 3·TM-γCD polyrotaxanes were synthesized by Suzuki coupling of 1 being in the form of its IC (1·TM-βCD or 1·TM-γCD) with 2 followed by the termination of the growing chains by bromobenzene, Scheme 1. To have the reference the neat copolymer 3