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

Decarboxylative and dehydrative coupling of dienoic acids and pentadienyl alcohols to form 1,3,6,8-tetraenes

• Ghina’a I. Abu Deiab,
• Mohammed H. Al-Huniti,
• I. F. Dempsey Hyatt,
• Emma E. Nagy,
• Kristen E. Gettys,
• Sommayah S. Sayed,
• Christine M. Joliat,
• Paige E. Daniel,
• Rupa M. Vummalaneni,
• Andrew T. Morehead Jr,
• Andrew L. Sargent and
• Mitchell P. Croatt

Beilstein J. Org. Chem. 2017, 13, 384–392, doi:10.3762/bjoc.13.41

• important problem in organic synthesis. Cross-coupling reactions provide avenues to these otherwise difficult reactions, but often require prefunctionalization of the coupling partners [1][2][3][4][5][6][7][8][9]. However, recent C–H activation research has enabled the use of further simplified starting

(Z)-Selective Takai olefination of salicylaldehydes

• Stephen M. Geddis,
• Caroline E. Hagerman,
• Warren R. J. D. Galloway,
• Hannah F. Sore,
• Jonathan M. Goodman and
• David R. Spring

Beilstein J. Org. Chem. 2017, 13, 323–328, doi:10.3762/bjoc.13.35

• , particularly in the field of total synthesis where it is often used to install vinyl iodides with high levels of geometric purity which can then be utilised in metal-catalysed cross-coupling reactions [2][6]. Hodgson et al. [7] and later Takai et al. [5] have proposed very similar models to explain the (E

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• elaboration of a new synthetic procedure. In this communication we present a detailed study of cross-coupling reactions between еthyl 3-decyl-2,2'-bithiophene-5-carboxylate and different aryl halides. The resulting esters are subsequently used as substrates in the preparation of new D–A–D compounds with an

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

• showed a good catalytic efficiency for both Suzuki and Heck cross-coupling reactions. The favorable effect originated from the ring-fused framework being able to establish a strained environment for better stability. Efficient couplings were achieved with aryl bromides or iodides as substrates, however

• up to 325 °C. With these sterically hindered iminopyridine–palladium complexes Pd1 to Pd5 in hand, we firstly investigated their catalytic activity directly in Suzuki cross-coupling reactions with chlorobenzene as the electrophile. The reactions were performed under the previously reported conditions

• , 27.9, 27.7, 27.2, 23.6, 23.5, 21.0; HRMS (ESI+) m/z: [M – Cl + CH3CN]+ calcd for C22H28ClN2Pd·CH3CN, 504.1235; found, 504.1231. General procedure for Pd-catalyzed Suzuki cross-coupling reactions To a Young tube, aryl chlorides (5.0 mmol), K2CO3 (1.5 g, 11 mmol), arylboric acid (6 mmol), complex Pd2

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• in the literature for other palladium-catalyzed cross-coupling reactions [34][35][36], namely in some reactions involving halogenated porphyrin derivatives [37]. Presumably in this particular case the lack of efficiency of the catalytic system is probably responsible for this secondary reaction

• -catalyzed cross-coupling reaction between aryl halides and N-tosylhydrazones. A retrosynthetic scheme for the synthesis of β-alkenyl-type porphyrin derivatives from the Zn(II) complex of β-bromo-meso-tetraphenylporphyrin and N-tosylhydrazones. Palladium catalysed cross-coupling reactions between β

• -brominated porphyrin 1 and N-tosylhydrazones 2a–c. Results obtained in the palladium-catalyzed cross-coupling reactions between β-brominated porphyrin 1 with N-tosylhydrazones 2a–c. Supporting Information Supporting Information File 46: Copies of NMR, HRMS(ESI) and UV–vis spectra of the new derivatives

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

• . This was exemplarily demonstrated by the hydrogenation of syn-21 and anti-24 and by a click reaction of a 5-alkynyl-substituted precursor. Keywords: amino alcohol; click reaction; cross-coupling reactions; hydrogenation; iodination; 1,2-oxazines; Introduction Over the last decade, we have intensively

• [21][22]. We previously reported the synthesis of enantiopure 1,2-oxazin-4-yl nonaflates and phosphates starting from precursors of type 3 and their conversion into differently C-4-substituted products employing palladium-catalyzed cross-coupling reactions [23]. In a related study, we have also

Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

• Lukas J. Patalag and
• Daniel B. Werz

Beilstein J. Org. Chem. 2016, 12, 2739–2747, doi:10.3762/bjoc.12.270

• membranes. Results and Discussion Synthesis The most prominent methods to access oligoene structures are either cross-coupling reactions [17][18][19] or Wittig-type reactions [20][21][22]. The advantage of the latter ones is that they are often conducted at low temperatures and therefore are employed for

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• cross-coupling reactions, cycloaddition reactions, radical reactions and reductive addition reactions. A terminal alkyne can also react as nucleophile or serve as synthon for pyrrole rings [24][25]. Thus we here fuse the rich alkyne chemistry to the EDOT backbone, resulting in a novel EDOT derivative

From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer

• Ming Liu,
• Jan C. Namyslo,
• Martin Nieger,
• Mika Polamo and
• Andreas Schmidt

Beilstein J. Org. Chem. 2016, 12, 2673–2681, doi:10.3762/bjoc.12.264

• tautomer; imidazol-2-ylidene; mesoionic compound; mesomeric betaine; Introduction Since the first isolation of a stable N-heterocyclic carbene (NHC) [1] in 1991 this compound class has provided numerous highly efficient ligands of NHC-metal catalysts for cross-coupling reactions [2][3][4][5][6][7

Facile synthesis of a 3-deazaadenosine phosphoramidite for RNA solid-phase synthesis

• Elisabeth Mairhofer,
• Elisabeth Fuchs and
• Ronald Micura

Beilstein J. Org. Chem. 2016, 12, 2556–2562, doi:10.3762/bjoc.12.250

• yield. Unfortunately, all attempts of the authors to displace the second chlorine atom of the imidazo[4,5-c]pyridine nucleoside using sodium methoxide or palladium-catalyzed cross-coupling reactions as described in [26] failed. We therefore decided not to put additional efforts into this route. Attempts

Sydnone C-4 heteroarylation with an indolizine ring via Chichibabin indolizine synthesis

• Florin Albota,
• Mino R. Caira,
• Constantin Draghici,
• Florea Dumitrascu and
• Denisa E. Dumitrescu

Beilstein J. Org. Chem. 2016, 12, 2503–2510, doi:10.3762/bjoc.12.245

• ; Chichibabin synthesis; indolizine; pyridinium N-ylide; sydnone; Introduction In recent decades, interest in the syntheses of biheteroaryls has been focused on the creation of new hetaryl–hetaryl C(sp2)–C(sp2) bonds, in particular through cross-coupling reactions. These reactions are catalyzed by palladium or

• formation of single bonds between two aromatic or heteroaromatic rings involves palladium-catalyzed cross-coupling reactions and cyclization of functional groups attached to an aromatic and heteroaromatic ring. Thus, arylation and heteroarylation at the C-4 position of sydnones has been performed by

• palladium-catalyzed cross-coupling reactions [32][33][34][35][36] starting from 4-unsubstituted sydnones, 4-halosydnones or by chemical transformation of the substituents attached to C-4 [32][33][34][35][36]. Herein, using the Chichibabin indolizine reaction one of the simplest and most efficient methods

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• π-bridges by simple Suzuki–Miyaura cross-coupling reactions could be completed. Starting with commercially available 5-bromothiophene-2-carboxaldehyde and then reaction with 3a–c to generate the required bithiophenes, then terthiophenes, while further catenation with 3b resulted in synthesis of the

Rapid regio- and multi-coupling reactivity of 2,3-dibromobenzofurans with atom-economic triarylbismuths under palladium catalysis

• Maddali L. N. Rao,
• Jalindar B. Talode and
• Venneti N. Murty

Beilstein J. Org. Chem. 2016, 12, 2065–2076, doi:10.3762/bjoc.12.195

• bromobenzofurans were not reported so far (Scheme 1) [35]. Given the importance of threefold couplings’ reactivity realized with the sub-stoichiometric loading of triarylbismuths in the cross-coupling reactions [35][36][37][38][39][40][41][42], we report herein, a novel regio- and multi-coupling of

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• analogs for the synthesis of L3 and L4 were synthesized according to literature procedures and used without purification [35][36]. The Stille cross coupling reactions for the synthesis of L3 and L4 were monitored by MALDI–TOF–MS and were found to not be complete after increasing the reaction time to 48 h

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

• para-position relative to nitrogen (the 6-position) was required for further functionalisation by typical cross-coupling reactions. THQ scaffolds similar to 1 are known in the literature, and have been typically prepared by two approaches. The first involves the alkylation of the starting aniline with

• was to synthesise THQs and DHQs of the general scaffold 1 for the use in a variety of cross-coupling reactions, thus necessitating the presence of a halogen or pseudohalogen in the para-position relative to nitrogen. Most of the relevant literature focuses on the synthesis of the corresponding aryl

• bromides or aryl chlorides, but initial investigation with 6-bromo-THQs indicated that these were remarkably unreactive in cross-coupling reactions [14], and a reliable and scalable synthesis of the likely more reactive iodides was, therefore, sought. We first considered the retrosynthetic analysis shown

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

• Dirk Meyer and
• Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

• ]. One of the most prominent examples are the palladium catalyzed cross-coupling reactions [2], but in addition palladium complexes recently received much attention also in the field of selective CH oxidations [3][4][5][6]. The catalytic conversion of alkanes and especially of methane into a value-added

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

• Mizuki Yamada,
• Mio Matsumura,
• Yuki Uchida,
• Masatoshi Kawahata,
• Yuki Murata,
• Naoki Kakusawa,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2016, 12, 1309–1313, doi:10.3762/bjoc.12.123

• organoantimony compounds in organic synthesis has attracted much interest during the last two decades [25][26]. Trivalent organoantimony compounds (stibanes) such as aryl- and ethynylstibanes are useful transmetalation agents in Pd-catalyzed cross-coupling reactions with aryl halides and acyl chlorides [27][28