Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• antitumour agents [10]. Advantages of the Suzuki–Miyaura coupling are mild reaction conditions, commercial availability of a large number of boronic acids and simple product purification [7]. Concerning the transition metal source for C–C cross-coupling reactions, homogeneous and heterogeneous Pd catalysts

• for catalysts rich in tin. Suzuki–Miyaura coupling reactions Batch reactions The catalytic activity of the synthesised catalysts in the Suzuki–Miyaura reaction was investigated using phenylboronic acid 3 in combination with various bromoarenes 4a–e, featuring ortho- and para-substitution of electron

• Ce0.20Sn0.79Pd0.01O2–δ particles after one month, (b) optical microscope image of the emulsion at 0.1 wt % particles. Suzuki–Miyaura coupling of phenylboronic acid 3 with various bromoarenes 4a–e (a: R1 = H, R2 = CH3; b: R1 = H, R2 = OH; c: R1 = H, R2 = COOCH3; d: R1 = H, R2 = CF3; e: R1 = CN, R2 = H). x90 and

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

• a more straightforward and versatile synthetic route. The Stille coupling was changed to a Suzuki–Miyaura coupling and the cyclization was performed directly starting from the free aniline nitrogen, as we found that Boc protection was required only for cyclization when using DBU and DABCO. To faster

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

• of their low reactivity. Recently, Li and Su with co-workers have developed a liquid-assisted grinding (LAG) method for the Suzuki–Miyaura coupling between aryl chlorides and boronic acids to synthesize the biaryls in nearly quantitative yield. Under optimized conditions 2 mol % Pd(OAc)2 and 4 mol

• ]. Mechanochemical Suzuki reaction [56]. Mechanochemical Suzuki–Miyaura coupling by LAG [57]. Mechanochemical Heck reaction [59]. a) Sonogashira coupling under milling conditions. b) The representative example of a double Sonogashira reaction of p-iodoacetophenone with 1,4-bis-ethynyl benzene. Copper-catalyzed CDC

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• H2PdCl4 in the presence of poly(N-vinylpirrolidone) (PVP) [46][47]. These Pd NPs exhibited highly efficient catalytic activity in Suzuki–Miyaura coupling reactions [46][47] and nitroaromatic hydrogenations [48] in aqueous medium. Outstanding performance of these PVP-Pd NPs in the coupling reaction was

• –Miyaura coupling reaction [46] and nitroaromatic hydrogenation [48], the PVP-Pd NPs catalytic system exhibited high catalytic activity after five cycles. In the Heck–Mizoroki coupling reaction under MW irradiation, once the reaction was completed, a new batch of reagents was added to the reaction tube and

• , precipitation or organic extraction eventually lead to a dramatic drop of the catalytic activity. As a result of this, and in order to perform the reuse experiment, repeated runs on the same batch were performed; reusing the reaction mixture with the PVP-Pd nanocatalyst. By this procedure in both, Suzuki

Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

• Kohei Yamada,
• Naoto Kamimura and
• Munetaka Kunishima

Beilstein J. Org. Chem. 2017, 13, 1478–1485, doi:10.3762/bjoc.13.146

• one-pot oxazole synthesis/Suzuki–Miyaura coupling sequence has been developed. One-pot formation of 5-(triazinyloxy)oxazoles using carboxylic acids, amino acids and a dehydrative condensing reagent, DMT-MM, followed by Ni-catalyzed Suzuki–Miyaura coupling with boronic acids provided the corresponding

• 2,4,5-trisubstituted oxazoles in good yields. Keywords: one-pot oxazole synthesis; Suzuki–Miyaura coupling; triazine; 5-(triazinyloxy)oxazole; trisubstituted oxazole; Introduction Oxazoles are found in numerous natural products and are used as a broad range of artificial compounds [1][2]. In

• , Jin and co-workers reported that Ni-catalyzed Suzuki–Miyaura coupling between triazinyloxybenzene and arylboronic acids affords the corresponding biaryl compounds [24][25][26][27][28][29][30][31][32][33]. In this context, we envisioned application of this Suzuki–Miyaura coupling to a 5-(triazinyloxy

Total synthesis of elansolids B1 and B2

• Liang-Liang Wang and
• Andreas Kirschning

Beilstein J. Org. Chem. 2017, 13, 1280–1287, doi:10.3762/bjoc.13.124

• iodide 17 after O-acylation, iodination of the terminal alkyne and finally diimide-mediated syn-reduction [11]. Next, DDQ-mediated removal of the PMB protecting group yielded vinyl iodide 18. The synthesis of both fragments 13 and 18 set the stage for the Suzuki–Miyaura coupling which delivered the

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

• Flavio Fanelli,
• Giovanna Parisi,
• Leonardo Degennaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

• polyfunctionalized biaryls, using a flow microreactor, has been recently reported by Yoshida [54]. Using the integrated microflow system reported in Scheme 8, arylboronic esters were prepared by a lithiation/borylation sequence, and used in a Suzuki–Miyaura coupling in a monolithic reactor. A remarkable aspect of

• the process was the use of an integrated supported monolithic Pd(0) catalyst that allowed to perform cross-coupling reactions in continuous flow mode (Scheme 8). This integrated microflow system allow to handle the borylation of aryl halides (Ar1X), and the subsequent Suzuki–Miyaura coupling using

• different aryl halide (Ar2X). Without requiring the protection of sensitive functionalities, running the flow system using a residence time (tR) of about 4.7 min at a temperature above 100 °C, high yields of coupling products were obtained. Noteworthy, the Suzuki–Miyaura coupling did not require the use of

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

• , since it is well documented that in related cross-coupling reactions of 16 exclusively the Z-isomers are formed [40]. The 5-iodo-1,2-oxazines syn-4a,b reacted smoothly under standard conditions of Suzuki–Miyaura coupling reactions [45] with vinylboronic acid 18 and 3-methoxyphenylboronic acid 20 to

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

• the Suzuki–Miyaura coupling [11]. A retrosynthetic analysis (Figure 3) of extended mono-functionalized triazinetricarboxylic acids 2 calls for tris(4-bromoaryl)-1,3,5-triazines 3 and boronic acids 4 with an additional carboxylic acid functionality. The respective methyl carboxylate of boronic acid 4

• ) MeOH/H2SO4, MeOH, 16 h, reflux, 94%, c) Me2SO4, K2CO3, acetone, 3 h, reflux, quant., d) MeI, K2CO3, DMF, 16 h, room temperature, 83%, e) NaOH, H2O, MeOH, 6 h, room temperature, 66%, f) SOCl2, DMF (cat.), 2 h, reflux, not isolated. Triple Suzuki–Miyaura coupling between tribromotriazines 3 and boronic

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• ”), there was a noticeable drop in the extent of conversion. In addition, lower loadings of HBF4, silver salt, or the palladium catalyst also gave inferior results. In the case of C–H activation/Suzuki–Miyaura coupling reactions, the commercially available, pre-formed cationic Pd(II) catalyst [Pd(MeCN)4

• Suzuki–Miyaura coupling reactions were applicable to a broader substrate scope than the corresponding reaction with aryl iodides, although the latter protocol remains appealing for a variety of cross-coupling combinations due to both the convenience of aryl iodides as substrates, and the use of water as

• traditional Suzuki–Miyaura coupling. It is used to control a range of plant pathogens in broadacre and horticultural crops (Scheme 6) [207]. Felpin and co-workers have reported its synthesis starting from aryldiazonium salts [208], while the Heinrich group has employed a free-radical biaryl cross-coupling of

Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

• Phil M. Pithan,
• David Decker,
• Manlio Sutero Sardo,
• Giampietro Viola and
• Heiko Ihmels

Beilstein J. Org. Chem. 2016, 12, 854–862, doi:10.3762/bjoc.12.84

• Pharmacological Sciences, via Marzolo 5, 35131 Padova, Italy University of Padova, Department of Woman’s and Child’s health, 35128 Padova, Italy 10.3762/bjoc.12.84 Abstract Cationic biaryl derivatives were synthesized by Suzuki–Miyaura coupling of 3-bromonaphtho[1,2-b]quinolizinium bromide with arylboronic acids

• -arylnaphtho[1,2-b]quinolizinium derivatives and demonstrate that some of these compounds have fluorosolvatochromic properties. Results Synthesis The 3-arylnaphtho[1,2-b]quinolizinium derivatives 6a–e were prepared by Suzuki–Miyaura coupling reactions with the 3-bromonaphtho[1,2-b]quinolizinium bromide (4

• -benzylpyridinium derivative 3 and the subsequent cyclodehydration [27] in refluxing HBr (w = 48%) gave the bromonaphtho[1,2-b]quinolizinium 4 in 57% overall yield (Scheme 1). The Suzuki–Miyaura coupling reactions of 3-bromonaphthoquinolizinium derivative 4 with the arylboronic acids 5a–e were performed under

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• substituted 3,5-diaryl-2,4,6-trimethylpyridines were prepared and characterized using the Suzuki–Miyaura coupling reaction with accordingly selected bromo-derivatives and arylboronic acids. The reaction conditions were carefully optimized allowing high yield of isolated products and also the construction of

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• benzylation, fully characterized and subjected to palladium catalyzed Suzuki–Miyaura coupling with 2-pyridineboronic acid N-phenyldiethanolamine ester to give the corresponding 2-pyridyl spiro-oxazoline (PyOx) ligands. The spiro-oxazoline ligands showed high asymmetric induction (up to 93% ee) when applied as

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• (PdNPs) affording highly active catalysts for Suzuki–Miyaura coupling reactions. Cobalt-containing polymers The incorporation of other late transition metals such as cobalt into polymers soon emerged as an efficient and rapid method for the production of nanostructured materials of scientific and

Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η⁵-Cp)Pd(IPr)Cl with (η³-cinnamyl)Pd(IPr)(Cl) and (η³-1-t-Bu-indenyl)Pd(IPr)(Cl)

• Patrick R. Melvin,
• Nilay Hazari,
• Hannah M. C. Lant,
• Ian L. Peczak and
• Hemali P. Shah

Beilstein J. Org. Chem. 2015, 11, 2476–2486, doi:10.3762/bjoc.11.269

• be closely related to cyclopentadienyl (Cp) ligands [17]. Nevertheless, to the best of our knowledge there are only two reports describing the catalytic activity of complexes of the type (η5-Cp)Pd(NHC)(Cl) for the Suzuki–Miyaura coupling, as well as related cross-coupling reactions [18][19]. These

• and tBuInd [16]. Cp was treated with base in the presence of ten equivalents of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (dvds) under a variety of conditions which are relevant to the Suzuki–Miyaura coupling and the reaction followed using 1H NMR spectroscopy (Table 1). The metal containing product

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• N-allylation afforded 125 (98%). The treatment of compound 125 with n-BuLi followed by alkylation with allyl bromide gave diallylindole 127 (77%), which on further treatment with 9-BBN (6 equiv) gave the doubly hydroborated species 128. Then, it was directly subjected to the Suzuki–Miyaura coupling

• a key step. The L,L-cyclodi(iodotryrosin) (131) was subjected to a benzylation reaction to give the protected compound 132 (76%). A one-pot Pd-catalyzed borylation and Suzuki–Miyaura coupling was employed to generate the cross-coupling product 134 (42%). Finally, deprotection of 134 was carried out

• derivative 159 (Scheme 24). To prepare π-conjugated three-dimensional molecules with potential isoelectronic properties and facile processibility, Kurata and co-workers [146] reported sexithiophene 163, a bridged cage shaped compound (Scheme 25). Its synthesis involves a Suzuki–Miyaura coupling reaction

A hybrid electron donor comprising cyclopentadithiophene and dithiafulvenyl for dye-sensitized solar cells

• Gleb Sorohhov,
• Chenyi Yi,
• Michael Grätzel,
• Silvio Decurtins and
• Shi-Xia Liu

Beilstein J. Org. Chem. 2015, 11, 1052–1059, doi:10.3762/bjoc.11.118

• –Miyaura coupling reaction between 4,4,5,5-tetramethyl-2-(4-(4,4,5,5-tetramethyl-1,3-dioxolan-2-yl)phenyl)-1,3,2-dioxaborolane and 6-bromo-4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b’]dithiophene-2-carbaldehyde [23]. All these new precursors and the two target dyes 1 and 2 were purified by chromatography and

• , the synthesis of the key intermediate 7 involves the protection of one aldehyde group as an acetal using pinacol prior to HWE reaction of 5 with 4,5-bis(hexylthio)-1,3-dithiole-2-thione, followed by deprotection under acidic conditions. Aldehyde 5 was readily obtained by palladium-catalyzed Suzuki

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• reported operation, the substrates of biaryl derivatives that contained phosphate with axial chirality were obtained in high yields using the Suzuki–Miyaura coupling reaction with the assistance of this versatile chiral ligand [31][32][33][34]. We used substituted naphthylboronic acid or ortho-substituted

• were successfully synthesized using the Suzuki–Miyaura coupling reaction under the assistance of a chiral ligand. Moreover, the substrates were further C–H functionalized using the P(O)Ar2 directing role with Pd salt as catalyst. Notably, the reactions took place in air atmosphere and at high

Aryl substitution of pentacenes

• Andreas R. Waterloo,
• Anna-Chiara Sale,
• Dan Lehnherr,
• Frank Hampel and
• Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

• opportunity to vary the pendent substituent through a Pd-catalyzed cross-coupling protocol (Scheme 2). Thus, pentacene 3g was treated under Suzuki–Miyaura coupling conditions with arylboronic acids, and the desired pentacenes 3j,k were obtained in yields of 92 and 68%, respectively. Notably, anthracenyl

Clean and fast cross-coupling of aryl halides in one-pot

• Valerica Pandarus,
• Geneviève Gingras,
• François Béland,
• Rosaria Ciriminna and
• Mario Pagliaro

Beilstein J. Org. Chem. 2014, 10, 897–901, doi:10.3762/bjoc.10.87

• Table 1 show that 3-bromophenol and 4-bromoanisole are entirely converted into the boronic acid pinacol ester in 2–3 h over 2 mol % SiliaCat DPP-Pd. The same aryl halides are coupled with 4-bromotoluene or 2-bromotoluene to form the Suzuki–Miyaura coupling product in, respectively, 85% and 92% yield in

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• an encapsulated palladium catalyst by Baxendale and Ley, et al. [25], the latter to process multigram quantities in a microwave-assisted Suzuki–Miyaura coupling. A comparison on the use of palladium(0) nanoparticle catalysts on glass-polymer composite materials in batch and flow-through experiments

Synthesis of enones, pyrazolines and pyrrolines with gem-difluoroalkyl side chains

• Assaad Nasr El Dine,
• Ali Khalaf,
• Danielle Grée,
• Olivier Tasseau,
• Fares Fares,
• Nada Jaber,
• Philippe Lesot,
• Ali Hachem and
• René Grée

Beilstein J. Org. Chem. 2013, 9, 1943–1948, doi:10.3762/bjoc.9.230

• –Miyaura coupling [35] gave biphenyl derivative 7e in 82% yield, while the Heck [36] and Sonogashira [37] reactions afforded also the desired targets 8e and 9e in 72% and 77% yield respectively. Similar results were obtained in Pd-mediated reactions starting from pyrroline 6e, as indicated in Scheme 8. The

• possibility of using these molecules as scaffolds for the preparation of focused chemical libraries. In order to explore this possibility we developed representative examples of Pd-catalyzed reactions starting from p-bromo derivatives 4e and 6e. The results are given in Scheme 7 for pyrazoline 4e. Suzuki

Incorporation of perfluorohexyl-functionalised thiophenes into oligofluorene-truxenes: synthesis and physical properties

• Neil Thomson,
• Alexander L. Kanibolotsky,
• Joseph Cameron,
• Tell Tuttle,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2013, 9, 1243–1251, doi:10.3762/bjoc.9.141

• -iodo-4-perfluorohexylthiophene, which was separated by column chromatography. Compound 4 then underwent Suzuki–Miyaura coupling with compound 5, which was synthesised according to our previously published method [17], and the product obtained, 6, was deprotected by bromination to give compound 7 and

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• hydride-AIBN initiated radical cyclization [33][34]. In 2005, Player and co-workers reported a tandem Heck/Suzuki–Miyaura coupling process for the synthesis of (E)-3,3-(diaryl)oxindoles [35][36][37]. Recently, alkenylation of indolin-2-ones has been developed by palladium-catalyzed aromatic C–H activation

Synthesis and structure of trans-bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride and diacetate. Suzuki–Miyaura coupling of polybromoarenes with high catalytic turnover efficiencies

• Jeelani Basha Shaik,
• Venkatachalam Ramkumar,
• Babu Varghese and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2013, 9, 698–704, doi:10.3762/bjoc.9.79

• Abstract trans-Bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride has been shown to be an excellent catalyst for the multiple Suzuki–Miyaura coupling reactions of polybromoarenes to the corresponding fully substituted polyarylarenes. The reactions proceeded in excellent yields and

• structures of the chloro (1) as well as the corresponding acetato (2) complexes are also reported and compared with the corresponding complexes of 1,4-diphenyl-3-methyl-1,2,3-triazol-5-ylidene as the ligand. Keywords: C–C coupling; N-heterocyclic carbene; palladium; Suzuki–Miyaura coupling; 1,2,3

• reactions one often encounters the formation of partially coupled products and incomplete reactions leading to problematic separation of pure fully substituted compounds. Herein we report very clean multiple Suzuki–Miyaura coupling of polybromoarenes. In every case reported herein the final product, namely