Bromide-assisted chemoselective Heck reaction of 3-bromoindazoles under high-speed ball-milling conditions: synthesis of axitinib

• Jingbo Yu,
• Zikun Hong,
• Xinjie Yang,
• Yu Jiang,
• Zhijiang Jiang and
• Weike Su

Beilstein J. Org. Chem. 2018, 14, 786–795, doi:10.3762/bjoc.14.66

• [33][34] and axitinib [35][36][37][38] (Scheme 1). Mechanochemistry as a burgeoning technique to promote solvent-free reactions has led to remarkable advances [39][40][41][42], particularly for cross-coupling reactions [43][44][45], involving Heck coupling with the aid of stoichiometric amounts of

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

• better yields and easier catalyst recover [26] than traditional processes. Lipshutz and co-workers have successfully exploited micelles not only as nanoreactors, but as an outstanding platform for achieving greener organic reactions [26][65][66]. They have shown, for example, C–N cross-coupling reactions

• -coupling reactions. Catalytic activity was compared to the activity of the freshly prepared free catalyst, and the palladium entrapment did not affect either the conversion or the yields of the reaction [28]. The catalyst immobilization also allowed facile Pd removal from the final product and catalyst

• hydrophobic membrane and as a consequence a higher reaction rate. Dergunov et al. reported on the design of a porous polymeric nanoreactor with a lipid bilayer for coupling reactions [87]. These nanocapsules were loaded with palladium catalysts and successfully used in Suzuki, Sonogashira and Heck cross

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

• development of heterogeneous Pd catalysts that are ready to be used in combination with biocatalysts for catalytic cascade synthesis of active pharmaceutical ingredients (APIs). In particular, we focus on the application of the catalytic systems for Suzuki–Miyaura cross-coupling reactions, which is the key

• minimal leaching behaviour is demonstrated with various Suzuki–Miyaura cross-coupling reactions in batch as well as in continuous flow employing the so-called “plug & play reactor”. Finally, we demonstrate the use of these particles as the sole emulsifier of oil–water emulsions for a range of oils

• , Pd-catalysed C–C cross-coupling reactions have become indispensable in many modern synthetic protocols both in the laboratory and on an industrial scale. A highly important representative of this class of transformation is the Suzuki–Miyaura reaction [5][6], involving the coupling of aryl halides

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• fluorine) may be generated in good yields and further functionalized through nucleophilic aromatic substitution or cross-coupling reactions. It was found that the products were stable in dilute aqueous solutions, but they slowly hydrolyzed in concentrated solutions or in the presence of other strong acids

• . SNAr reactions of fluoro-substituted benzamide derivatives. Cross-coupling reactions of N-triflylbenzoic acid derivatives. Hydrolysis rates of the 4-bromobenzoic acid derivatives. Supporting Information Supporting Information File 42: NMR spectra of synthesized compounds. Acknowledgements The Danish

Palladium-catalyzed ortho-halogenations of acetanilides with N-halosuccinimides via direct sp² C–H bond activation in ball mills

• Zi Liu,
• Hui Xu and
• Guan-Wu Wang

Beilstein J. Org. Chem. 2018, 14, 430–435, doi:10.3762/bjoc.14.31

• construction of C–X bonds. With the development of transition-metal-catalyzed cross-coupling reactions, a series of halogenations at the ortho-position of the directing groups have been disclosed [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Nevertheless, from the viewpoint of green chemistry, the

Recent developments in the asymmetric Reformatsky-type reaction

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 325–344, doi:10.3762/bjoc.14.21

• ][8][9][10][11][12][13]. Moreover in 2014, two book chapters dealing with organozinc reagents were published covering the literature up to 2011 [14][15], and a review focusing on general SmI2-mediated cross-coupling reactions including only two references dated of 2013 concerning diastereoselective

One-pot sequential synthesis of tetrasubstituted thiophenes via sulfur ylide-like intermediates

• Jun Ki Kim,
• Hwan Jung Lim,
• Kyung Chae Jeong and
• Seong Jun Park

Beilstein J. Org. Chem. 2018, 14, 243–252, doi:10.3762/bjoc.14.16

• methods [44][45][46][47][48][49]. In general, Pd-catalyzed Suzuki–Miyaura cross-coupling reactions are the most popular synthetic strategy for aryl–aryl bond-forming reactions [50][51][52]. However, it has been reported that the Suzuki cross-coupling of nitrogen- and sulfur-containing heterocycles is more

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

• Futa Ogawa,
• Masanori Takeda,
• Kanae Miyanaga,
• Keita Tani,
• Ryuji Yamazawa,
• Kiyoshi Ito,
• Atsushi Tarui,
• Kazuyuki Sato and
• Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

• groups. The data in Table 1 show that Hiyama cross-coupling reactions gave the desired TFPE-anilines and TFPE-phenylenediamines (1–4) in moderate to good yields. This method has the advantage that complete substitution of diiodo- and triiodoarenes can proceed to give disubstituted (1 and 3) and

• on addition of DPP-4. Use of 1 as fluorogenic probe for DPP-4 activity. Synthesis of fluorogenic probe H-Gly-Pro-1. Synthesis of TFPE-anilines 1–4 via Hiyama cross-coupling reactions of iodoanilines with (E)-trimethyl(3,3,3-trifluoroprop-1-enyl)silane.a UV–vis absorption and fluorescence data for 1–4

• fluorophore structure. This suggests that substitution with TFPE would be a reasonable approach to producing new fluorescent molecules. However, there are few methods for synthesizing TFPE-substituted compounds. In a previous study, we achieved the facile introduction of TFPE groups via Hiyama cross-coupling

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• ], gold-catalyzed azetidin-3-one formation [16], as well as various transition metal-mediated additions and cross-coupling reactions [17] represent further important reactions of propargylamines, providing the potential to form innovative peptidomimetics (Figure 2). Our attention has been focused on the

• , forming the scaffold of versatile peptidomimetics 11. According to the proposed rearrangement of alkyne 7 (Figure 9), the choice of base is crucial for such cross-coupling reactions. To get a better understanding of the reactivity of propargylamines, the stability and propensity for base induced

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• Engineering, Czestochowa University of Technology, Armii Krajowej 17, Czestochowa, 42-200, Poland 10.3762/bjoc.13.235 Abstract Nine new quadrupolar chromophores based on diketopyrrolopyrrole were designed and prepared by cross-coupling reactions. The property tuning has been achieved by structural variation

• and its final cross-coupling reactions (Scheme 1). The construction of the DPP central scaffold 6 was accomplished by a well-known reaction between thiophene-2-carbonitrile and dimethyl succinate in the presence of sodium tert-amylalcoholate generated in situ [32]. The reaction provided 6 with a high

• 7 using a larger excess of NBS resulted in its decomposition. According to the current literature reports [18][19][27], DPP derivative 8 undergoes smooth cross-coupling reactions. Hence, we have utilized twofold Suzuki–Miyaura and Migita–Stille reactions leading to chromophores 1a–3a and 4a

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

• ][91] or a peptide [92]. For example, TFEO-Pcs conjugated with peptides (15) have been reported [93]. A3B type TFEO-Pc was successfully condensed with peptides by palladium-catalyzed cross-coupling reactions in good yield (Scheme 5). These TFEO-Pc-peptide conjugates, which show a sharp Q band in the UV

Synthesis of substituted Z-styrenes by Hiyama-type coupling of oxasilacycloalkenes: application to the synthesis of a 1-benzoxocane

• James R. Vyvyan,
• Courtney A. Engles,
• Scott L. Bray,
• Erik D. Wold,
• Christopher L. Porter and
• Mikhail O. Konev

Beilstein J. Org. Chem. 2017, 13, 2122–2127, doi:10.3762/bjoc.13.209

• James R. Vyvyan Courtney A. Engles Scott L. Bray Erik D. Wold Christopher L. Porter Mikhail O. Konev Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA 98225, USA 10.3762/bjoc.13.209 Abstract Several Hiyama cross-coupling reactions of oxasilacycloalkenes and

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• catalyst. It is observed that the uniformly dispersed Ni NPs supported on RGO could exhibit excellent catalytic activity in C–S cross-coupling reactions and the catalytic application is generalized with diverse coupling partners. Although the electron-rich planar RGO surface helps in stabilizing the

• first palladium-catalyzed arylation of thiols was reported by Migita and co-workers in 1980 [5], and soon after Cristau and co-workers developed a nickel-catalyzed route for C–S cross-coupling reactions [6]. Other metals such as copper [7], cobalt [8], iron [9], rhodium [10], manganese [11], indium [12

• properties [14]. The Ni-catalyzed C–S cross-coupling reactions generally involved Ni salts [15][16][17][18], Ni–phosphine complexes [19][20][21], or Ni–NHC complexes [22][23], although the actual catalyst is believed to be a Ni(0)/Ni(I) species [16][17][18][19][20][21]. NiO supported on zirconia (NiO–ZrO2

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• -catalyzed cross-coupling reactions to form C–C bonds are very powerful synthetic tools in modern organic synthesis [7]. With their increasing applications in the synthesis of pharmaceuticals, natural products and functional materials [8][9][10], moving these useful transformations to occurring in aqueous

• media became more and more attractive [11]. Despite there are several strategies for palladium-catalyzed cross-coupling reactions in water, such as microwave heating [12], ultrasonic irradiation [13][14] and ligand-free methodology [15][16], the more efficient and preferable one is the use of water

• ligands, functionalized with sulfonate- [41][42][43][44][45][46], carboxylate- [47][48][49][50][51][52], polyether- [53][54][55][56][57][58][59] and other hydrophilic groups [60][61][62][63], have been developed and used in the aqueous Pd-catalyzed cross-coupling reactions. Among them, most of them were

Encaging palladium(0) in layered double hydroxide: A sustainable catalyst for solvent-free and ligand-free Heck reaction in a ball mill

• Wei Shi,
• Jingbo Yu,
• Zhijiang Jiang,
• Qiaoling Shao and
• Weike Su

Beilstein J. Org. Chem. 2017, 13, 1661–1668, doi:10.3762/bjoc.13.160

• easily recovered and reused for at least five times without significant loss of catalytic activity. Keywords: ball milling; Heck reaction; layer double hydroxides; solvent-free; supported Pd catalyst; Introduction High-speed ball milling (HSBM)-assisted transition metal-catalyzed cross-coupling reactions

• %), TBAB (1.5 mmol), K2CO3 (3.6 mmol), and silica gel 5 g were placed in a 80 mL stainless-steel vessel (ΦMB = 0.25, dMB = 5 mm). HSBM conditions: 60 min at 800 rpm. Supported catalysts in cross-coupling reactions. MM represents mixer mill; PM represents planetary mill. Selected model reaction. Pd/MgAl

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

• ], published in 2007, Kishi and co-workers increased the overall efficiency of the synthesis by reorganizing the assembly of the principal fragments and by optimizing the key C(sp2)–C(sp3) Negishi cross-coupling reactions as well as the choice of protecting groups. The 3rd generation approach [123], published

• mycolactone core structure is depicted in Scheme 1. It relied on two consecutive Negishi cross-coupling reactions [124] to construct the linear C1–C20 fragment, which was to be cyclized by macrolactonization [39]. Vinyl iodide 19, corresponding to the C14–C20 part of the core extension, was synthesized from

A novel approach to oxoisoaporphine alkaloids via regioselective metalation of alkoxy isoquinolines

• Benedikt C. Melzer and
• Franz Bracher

Beilstein J. Org. Chem. 2017, 13, 1564–1571, doi:10.3762/bjoc.13.156

• species with ZnCl2 should lead to at C-1 zincated isoquinolines, which could undergo Negishi cross-coupling reactions with appropriately substituted methyl 2-bromobenzoates to give methyl 2-(isoquinolin-1-yl)benzoates. These would again open an access to oxoisoaporphine alkaloids via intramolecular

• , which were expected to be versatile substrates for Suzuki cross-coupling reactions with appropriate phenylboronic acids to gain methyl 2-(isoquinolin-1-yl)benzoates as the central intermediates (Scheme 1). Results and Discussion As we reported previously, metalation of 6,7-dimethoxyisoquinoline (7a) and

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

• thiazole units using cross-coupling reactions and Hantzsch-type condensation to a pyridine central platform. This second strategy has been first initially explored by Kelly in 1991 for the first preparation of heterocyclic core of micrococcinic acid [12][13] but due to the unique and original mode of

• the neat synthesis of GE2270 central core in 33% yield over a 4-step sequence (Figure 1) including three Negishi and Stille cross-coupling reactions to achieve the direct introduction of mono- and dithiazolyl units to a 2,3,6-trihalopyridine [17]. The strategy has then extended to the total synthesis

• 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

Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives

• Roman A. Irgashev,
• Nikita A. Kazin,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2017, 13, 1396–1406, doi:10.3762/bjoc.13.136

• ICZs [37], as well as C2- and C2,8-bromination of 6,12-disubstituted ICZs [23][38]. Bromo-containing ICZ derivatives have also been involved in further lithiation and metal-catalyzed cross-coupling reactions. Herein, we describe an effective protocol for nitration of 5,11-dihydroindolo[3,2-b]carbazoles

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

• ) was the installation of the side chain at C1–C13. The synthesis relied on two consecutive Sonogashira–Hagihara cross-coupling reactions that provided the ene–diyne system (C10–C15) 10 in good yield. However, partial hydrogenation (only the zinc–copper couple worked) furnished the desired (Z,E,Z

• elansolid B1 (2). The improvements are mainly associated with the preparation of the triene unit at C10–C15 by utilizing the Stille and the Suzuki–Miyaura cross-coupling reactions as well as the highly versatile difunctionalized building block 14. In principal, the synthesis sheds light on how such (Z,E,Z

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

• Adrián A. Heredia and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

• applications of alkynyl selenides are electrophilic addition reactions, many of them modulated by transition-metal catalysts [11]. Some examples are: hydroboration which results in a vinylborane selenide used in Pd-catalyzed Suzuki cross-coupling reactions [12], the addition to tributyltin hydride in the

• synthesis of seleno-functionalized heterocycles [20][21]. Recently, the use of alkynyl selenides as substrates for Pd-catalyzed Suzuki, Negishi, Kumada and Sonogashira cross-coupling reactions has been reported with good yields [22]. Due to the synthetic relevance of alkynyl selenides several methodologies

Synthesis of tetrasubstituted pyrazoles containing pyridinyl substituents

• Josef Jansa,
• Ramona Schmidt,
• Ashenafi Damtew Mamuye,
• Laura Castoldi,
• Alexander Roller,
• Vittorio Pace and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90

• corresponding 1,3,5-trisubstituted pyrazoles. Iodination at the 4-position of the pyrazole nucleus by treatment with I2/HIO3 gives the appropriate 4-iodopyrazoles which served as starting materials for different cross-coupling reactions. Finally, Negishi cross-coupling employing organozinc halides and Pd

• -protected pyrazoles [21] or sequential cross-coupling reactions starting from 3-iodopyrazole [22] have been described. Herein, we report the synthesis of fully substituted pyrazoles containing at least two pyridinyl substituents by combining the before mentioned approaches: reaction of 1,3-dipyridinyl-1,3

• 2a,b, 3a,b and 4a,b) strongly hints to the involvement of the former into an intramolecular hydrogen bond as indicated in Scheme 3. Cross-coupling reactions Initial attempts to react 4-bromopyrazole 5 – obtained from reaction of 2a with N-bromosuccinimide – with phenylboronic acid (or 3

Substitution of fluorine in M[C₆F₅BF₃] with organolithium compounds: distinctions between O- and N-nucleophiles

• Anton Yu. Shabalin,
• Nicolay Yu. Adonin and
• Vadim V. Bardin

Beilstein J. Org. Chem. 2017, 13, 703–713, doi:10.3762/bjoc.13.69

• ]. Over the last 15 years, we reported the successful application of polyfluorinated organoborates K[RC6F4BF3], K[C6F5B(OMe)3] and K[CF2=CFBF3] as boron-containing reagents in the Pd-catalyzed cross-coupling reactions with C-electrophiles [22][23][24][25][26][27]. Nowadays a common approach to these

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• with copper cation in comparison to bidentate ligands 5c and 5d. However, the cholane skeleton in 5c and 5d can be useful for integration of these ligands into lipophilic membranes. Conclusion Cu- and Pd-catalyzed cross-coupling reactions were applied for the preparation of arylamino derivatives of

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

• 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