Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

• Karolina Żukowska,
• Eva Pump,
• Aleksandra E. Pazio,
• Krzysztof Woźniak,
• Luigi Cavallo and
• Christian Slugovc

Beilstein J. Org. Chem. 2015, 11, 1458–1468, doi:10.3762/bjoc.11.158

• Suzuki coupling as shown in Scheme 2 [14]. The cyano-substituted compound 10 was obtained without difficulty, but esterification of compound 9 was problematic because of purification issues (cf. Supporting Information File 1) so an alternative pathway was established. Starting from 2-bromoaniline upon

• Doebner–Miller reaction and oxidation, we obtained the corresponding bromide derivative which was subsequently converted via Suzuki coupling into the carbene precursor 13. Both compounds 12 and 13 were then used in a carbene exchange reaction with compound 1 conducted in toluene at 80 °C (see Scheme 3

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• characterized. An optically active, (S)-(+)-methyl 3-hydroxy-2-methylpropionate is used to introduce a chiral center in the molecule. A biphenyl moiety prepared by Suzuki coupling reaction is directly attached to the oxadiazole core at C-5 position. Investigations for the phase behavior revealed that the series

• ; SmC* phase; spontaneous polarization; Suzuki coupling; Introduction The 1,2,4-oxadiazole derivatives are prevalently reported compounds with promising biological [1][2][3][4][5] and physiological [6][7][8] activity such as antiinflammatory, antibacterial, antimicrobial, antifungal, anticancer

• with two ester groups and a chiral center. This bromo-substituted chiral molecule is treated with boronate esters 6a/6b under Suzuki coupling conditions to get the final products with a biphenyl moiety directly attached to the oxadiazole core at C-5 position, 13ap–13as (Ph.Ox.C*Cn) / 13bp–13bs (C12

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• reaction. Ghosh, Dhara et al. also reported a synthesis of substituted phenanthridines based on palladium-mediated Suzuki coupling (Scheme 14) [34][35]. Aerobic ligand-free domino Suzuki coupling–Michael addition reaction in the presence of Pd(OAc)2 and K3PO4 as a catalytic system in H2O was catalysed by

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• -shaped molecules. The other series (T-Bn, n = 1–4) represents star-shaped systems with the arms in the meso- and β-positions, providing T-shaped molecules. Results and Discussion Synthesis For the synthesis of the Y-B1–Y-B4 series a convergent strategy was chosen (Scheme 1). The modified Suzuki coupling

• oligofluorenylboronic acids FnB (n = 1–4), synthesised by a known procedure [19], was used as the precursors for the nucleophilic coupling reagent. In the case of the T-Bn series, the convergent strategy was used for the synthesis of T-B1–T-B3 compounds using Suzuki coupling of the aforementioned oligofluorenyl boronic

• . Finally, Suzuki coupling of the bromo compound T-B1Br with terfluorenyl boronic acid F3B was achieved in 21% yield. The boronic acid SiFB was synthesised using a previously published procedure [23]. The core precursor T-B0Br was synthesised in 63% yield by using NBS as the brominating reagent instead of

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• bulk heterojunction OPVs with moderate power conversion efficiencies. Results and Discussion Synthesis Our synthetic approach was to prepare BODIPY derivatives bearing a brominated thiophene on the meso-position and coupling these derivatives via Suzuki coupling to the central DPP core 8 (Scheme 1

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• native γ-CD decrease [13]. Nevertheless, they are in good agreement with the reported stability constants of CDs with different molecules in organic solvents [36]. 4a and 4b polyrotaxanes and 4 non-rotaxane copolymer were obtained by firstly carrying out the well-known paladium-catalyzed Suzuki coupling

Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C₃₆H₁₂ open geodesic polyarene

• Hee Yeon Cho,
• Ronald B. M. Ansems and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2014, 10, 956–968, doi:10.3762/bjoc.10.94

• more details). In a reasonably dilute solution and with two equivalents of bromine, selective monobromination on the α-carbon of circumtrindene has been achieved with a quantitative yield (Scheme 8). With bromocircumtrindene 28 in hand, Suzuki coupling reactions were carried out with commercially

• available boronic acids. The reaction proceeds smoothly with 2-bromophenylboronic acid in the presence of Pd(0) and a base to furnish 29 (Scheme 9). The Suzuki reaction proceeds reasonably well, despite the potential complication of the product undergoing a subsequent Suzuki coupling with the bromine of the

• . Such a compound can be synthesized by replacing the bromo group of 28 with a 2,6-dimethyl substituted phenyl group (Scheme 10). The Suzuki coupling was again employed; compound 28 underwent the coupling reaction with 2,6-dimethylphenylboronic acid in the presence of a palladium catalyst [Pd(PPh3)4] and

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

• ]. Of direct relevance to this research report, Giroux and co-workers reported the homogeneously palladium-catalyzed one-pot borylation/Suzuki coupling reactions already in 1997 [7]. Yet, it remains desirable to efficiently heterogenize palladium catalytic species used in cross-coupling reactions with

• conversion of the original halides into the unsymmetrically coupled product. Results displayed in Table 1, entry 7 show that when 4-bromopyridine hydrochloride is replaced by 4-chloropyridine hydrochloride, only a 35% yield of the Suzuki coupling product is obtained in 3 h over 1 mol % Pd catalyst. The yield

• grows to 86% by prolonging the reaction time to 17 h. However, it is enough to add another 1 mol % Pd catalyst amount to the reaction mixture, after the borylation is complete, to observe 95% conversion into the Suzuki coupling product in 3 h (Table 1, entry 8). In conclusion, unsymmetrically coupled

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

• Mrinal K. Bera,
• Moisés Domínguez,
• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37

• the range of 60–72%. Pyrid-4-yl nonaflates are excellent precursors for transition metal-catalyzed cross-coupling reactions [42][54][55][56][57][58], which was demonstrated here by the successful Suzuki coupling of bisnonaflate 19 with (E)-styrylboronic acid and the Stille coupling of 19 with 2

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

• Suzuki coupling of tribromohexahexyltruxene 17, which was synthesised according to our previously published method [14], and the relevant boronic ester, 8 or 16 (Scheme 3). T4-4FTh (Scheme 4) was synthesised by coupling compound 16 with T3Br. The latter compound was obtained by our previously published

Palladium-catalyzed synthesis of N-arylated carbazoles using anilines and cyclic diaryliodonium salts

• Stefan Riedmüller and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2013, 9, 1202–1209, doi:10.3762/bjoc.9.136

• biphenyl derivative 4*HCl was prepared by Suzuki coupling of 2-iodoaniline and 2-bromophenylboronic acid. Diazotation of 4*HCl and cyclization gave the cyclic diarylbromonium chloride 5 as an off-white powder in good isolated yield (52%) (Supporting Information File 1) [41]. Finally, 5 could be converted

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• devices based on this compound. Results and Discussion Synthesis The synthesis of compound 2 was completed in a simple two-step procedure by using the strategy of Gupta et al. [20] (Scheme 1). A Suzuki coupling of the triarylaminoboronic acid 3 to the bromo-dihexylbithiophene-carboxaldehyde 4 [27

Camera-enabled techniques for organic synthesis

• Steven V. Ley,
• Richard J. Ingham,
• Matthew O’Brien and
• Duncan L. Browne

Beilstein J. Org. Chem. 2013, 9, 1051–1072, doi:10.3762/bjoc.9.118

• pressures. A camera allowed the interior of the reactor to be visualised so that phase measurements could be taken. (a) The video camera setup providing a view of the reaction within the microwave cavity; (b) a palladium-catalysed Suzuki coupling performed by using this arrangement; (c) the reaction vessel

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• catalyzed Suzuki coupling of the starting halide 73 and boronic acid 74 followed by N-methylation of 75 with [3H]methyl iodide and O-demethylation with sodium thiophenoxide (Scheme 6C). Compound 57 showed high affinity for Aβ1-40 fibrils in vitro (Kd = 8.4 nM) and lower background binding levels than 56c

• binding in vivo. Several [18F]-labeled benzofurans have been employed with success for Aβ imaging. [18F]FPYBF-1 (123a), which has a N,N-dimethyl-2-aminopyridine group attached to the benzofuran core, was synthesized via Suzuki coupling between 5-methoxybenzofuran-2-boronic acid (130) and 2-amino-5

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• -dioctylfluorene)-alt-5,5'-bithiophene/PS-βCD] (PDOF-BTc) polyrotaxane copolymer, through a Suzuki coupling reaction between the 5,5'-dibromo-2,2'-bithiophene (BT) inclusion complex with persilylated β-cyclodextrin (PS-βCD), and 9,9-dioctylfluorene-2,7-bis(trimethylene borate) (DOF) as the blocking group. The

Palladium-catalyzed substitution of (coumarinyl)methyl acetates with C-, N-, and S-nucleophiles

• Kalicharan Chattopadhyay,
• Erik Fenster,
• Alexander J. Grenning and
• Jon A. Tunge

Beilstein J. Org. Chem. 2012, 8, 1200–1207, doi:10.3762/bjoc.8.133

• reverse-phase HPLC (Waters Alliance 2795 system) with peak area (UV) at 214 nm. Approach to diversely substituted coumarins. Scope of the decarboxylative coupling. Scope of Suzuki-coupling of coumarinyl acetates. Coupling of (coumarinyl)methyl acetates with N- and S-nucleophiles. Scope of the coumarinyl

Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

• Matthias Böttger,
• Björn Wiegmann,
• Steffen Schaumburg,
• Peter G. Jones,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2012, 8, 1037–1047, doi:10.3762/bjoc.8.116

• acid for the Suzuki coupling. Crystals of the products could be grown and exhibited interesting structures by X-ray analysis, one of them showing a chain-like network with the adjacent molecules linked to each other via intermolecular N–H…N hydrogen bonds. Keywords: boronic acids; complex chemistry

• ; in situ generation; pyrrole-pyridine; Suzuki coupling; Introduction Tridentate ligands have recently received attention in the area of rare-earth-metal complex chemistry [1][2][3][4][5]. Many rare-earth-metal cations, such as europium(III), have the tendency to be nine-coordinating species. Besides

• the synthesis of the new structures 1–3. Results and Discussion Our first retrosynthetic approach included a Suzuki coupling of the alpha-substituted boronic acid of Boc-protected pyrrole 7 with the heteroaryl bromides 8–10, as shown in Scheme 3. Compound 7 is described in literature [10], but it

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• Scheme 1. Results and Discussion The synthesis route for diarylethenes 1o–3o is shown in Scheme 2. First, the benzaldehydethiophene derivatives 5a–c were prepared by Suzuki coupling of three bromobenzaldehyde derivatives with a thiopheneboronic acid 4 [38][39][40][41][42]. Second, 1,3-dioxolane

Synthesis and characterization of Sant-75 derivatives as Hedgehog-pathway inhibitors

• Chao Che,
• Song Li,
• Bo Yang,
• Shengchang Xin,
• Zhixiong Yu,
• Taofeng Shao,
• Chuanye Tao,
• Shuo Lin and
• Zhen Yang

Beilstein J. Org. Chem. 2012, 8, 841–849, doi:10.3762/bjoc.8.94

•  1. Accordingly, Suzuki coupling of 4-bromopyridine and 3-formylphenylboronic acid afforded biaryl aldehyde 2, which was then subjected to a reductive amination by condensation of aldehyde 2 with N-Boc-cyclohexane-1,4-diamine, followed by reduction with NaBH(OAc)3 to afford secondary amine 3

• heteroaryl ring, different pyridine and pyrimidine substituents were also incorporated. Generally, the compounds 10a–g were synthesized following the general route in Scheme 1, by using aldehydes 11a–g as key intermediates. As described in Scheme 5, 11a–d were prepared through Pd-catalyzed Suzuki coupling of

• type of structure. 19a–d were prepared through Suzuki coupling as described above, and 19e–g were obtained in 70–85% yield by Ullmann coupling of 3-bromobenzaldehyde with an excess of the appropriate amines 20e–g [49]. The Buchwald coupling of protected 3-bromobenzaldehyde with amines 20h–j proceeded

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• esters in organic synthesis is demonstrated by their use as key intermediates in transition-metal-catalysed bond-forming reactions [6], which include the Miyaura–Suzuki coupling reaction [7], copper-catalysed heteroatom arylation [8], allylboration [9], and the Petasis reaction [10]. Aryl boronic esters

Double N-arylation reaction of polyhalogenated 4,4’-bipyridines. Expedious synthesis of functionalized 2,7-diazacarbazoles

• Mohamed Abboud,
• Emmanuel Aubert and
• Victor Mamane

Beilstein J. Org. Chem. 2012, 8, 253–258, doi:10.3762/bjoc.8.26

• 2,7-diazacarbazole 3a showed a rather low reactivity of the C–Cl bonds in the 3- and 6-positions. Indeed, the Stille coupling [42] of 3a with 2-tributylstannylpyridine (8) afforded a mixture of mono- and di-functionalized compounds 9a and 9b in 40% and 33% yields, respectively. The Suzuki coupling [43

• were functionalized by a selective Suzuki coupling to give the new bipyridine derivatives 11a,b, which underwent the double N-arylation to afford 3,6-difunctionalized 2,7-diazacarbazoles 12a–c in good overall yields (Scheme 4). Single crystals of compounds 3b and 12c were obtained from evaporation of n

Directed aromatic functionalization in natural-product synthesis: Fredericamycin A, nothapodytine B, and topopyrones B and D

• Charles Dylan Turner and
• Marco A. Ciufolini

Beilstein J. Org. Chem. 2011, 7, 1475–1485, doi:10.3762/bjoc.7.171

• regard, we elected to prepare 42 by Suzuki coupling [85] between a furylboronic acid and a 2-chloroquinoline [86]. The (relative) acidity of the C-2 position of furan is such that n-BuLi without added TMEDA suffices to induce lithiation. Accordingly, treatment of commercial 2-ethylfuran with n-BuLi in

• THF at 0 °C and cannulation of the resulting mixture into a solution of trimethyl borate in THF afforded boronic acid 44 (Scheme 9) in 90% yield after the customary aqueous workup [87]. This material underwent smooth Suzuki coupling with the known 45 [81][82][83], and the action of aqueous NBS [88

Synthesis of diverse dihydropyrimidine-related scaffolds by fluorous benzaldehyde-based Biginelli reaction and post-condensation modifications

• Bruno Piqani and
• Wei Zhang

Beilstein J. Org. Chem. 2011, 7, 1294–1298, doi:10.3762/bjoc.7.150

• are used as common intermediates for post-condensation modifications such as cycloaddition, Liebeskind–Srogl reaction and Suzuki coupling to form biaryl-substituted dihydropyrimidinone, dihydropyrimidine, and thiazolopyrimidine compounds. The high efficiency of the diversity-oriented synthesis is

• achieved by conducting a multicomponent reaction for improved atom economy, under microwave heating for fast reaction, and with fluorous solid-phase extractions (F-SPE) for ease of purification. Keywords: Biginelli reaction; dihydropyrimidine; diversity-oriented synthesis; fluorous; Suzuki coupling

• intermediate for post-condensation reactions including cycloaddition, Liebeskind–Srogl reaction and Suzuki coupling to form three different heterocyclic skeletons. The high efficiency of the diversity-oriented synthesis was achieved by conducting fast, microwave-heated reactions and simple fluorous solid-phase

The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

• Bryan Ringstrand,
• Martin Oltmanns,
• Jeffrey A. Batt,
• Aleksandra Jankowiak,
• Richard P. Denicola and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2011, 7, 386–393, doi:10.3762/bjoc.7.49

• of the Pd catalyst with ZnBr2 permits efficient hydrogenation without loss of the halogen. The chlorophenyl derivative 3e is a convenient precursor to a variety of 4-alkylphenyl and 4-arylphenyl derivatives that can be obtained via Negishi or Suzuki coupling methods (i.e., 3d). Another such