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

• position 8 of 7-deazaadenine. For the synthesis of these 8 compounds we used a convergent approach based on a central Suzuki cross-coupling reaction (Scheme 1). For the compounds with one methyl group (1a–d), 7-deaza-7-iodo-2’-deoxyadenosine was synthesized as described [48], while 7-deaza-7-iodo-8-methyl

• of the closed ring form was measured over 1 h. Synthesis of 7-deaza-2’-deoxyadenosine photoswitches with one and two methyl groups via Suzuki cross-coupling [45]. Optimized route for synthesis of 7-deaza-7-iodo-8-methyl-2’deoxyadenosine (9). Synthesis of the boronic acid pinacolate esters. Absorption

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

• toluene/H2O (6:1) was initially tested. Recently, several ligand-free catalytic systems have been applied successfully in Suzuki cross-coupling reaction between various aryl and heteroaryl halides and triflates with alkenyl and arylboronic acids [40][41][42][43]. The evaluation of such catalysts

• convenient synthesis of symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction. Several diarylpyridines with mixed aryl rings were produced by sequential two-step Suzuki cross-coupling reaction with separation of intermediary 3-aryl-5

• , entry 8). Higher yields of products containing electron-withdrawing groups probably resulted from an increased reactivity of the monobromo intermediate toward the second cross-coupling reaction. This observation was mentioned by Minard et al. [59] in the course of a one-pot two-step Suzuki cross

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

• [2,7-(9,9-dioctylfluorene)-alt-2,7-fluorene/TM-βCD)] (3·TM-βCD) and poly[2,7-(9,9-dioctylfluorene)-alt-2,7-fluorene/TM-γCD)] (3·TM-γCD) polyrotaxanes have been synthesized. Thus, 3·TM-βCD and 3·TM-γCD have been obtained through the Suzuki cross-coupling reaction of 2,7-dibromofluorene (1) encapsulated

Versatile synthesis and biological evaluation of novel 3’-fluorinated purine nucleosides

• Hang Ren,
• Haoyun An,
• Paul J. Hatala,
• William C. Stevens Jr,
• Jingchao Tao and
• Baicheng He

Beilstein J. Org. Chem. 2015, 11, 2509–2520, doi:10.3762/bjoc.11.272

• Stille and Suzuki cross-coupling reactions. 3’-Deoxy-3’-fluororibofuranosyl 2-chloropurine nucleosides 17–20 were synthesized by the similar strategy from the key intermediate 42. DME–water was found to be an efficient solvent system for Suzuki reaction on challenging substrates. De-chlorination of the 6

• ’-deoxy-3’-fluororibosides 16–20. Synthesis of 2-aminopurine 3’-deoxy-3’-fluororibosides 21–23. C–C bond formation by Stille and Suzuki cross-coupling. Antitumor activity of newly synthesized compounds. Supporting Information Supporting Information File 444: Experimental procedures, characterization data

• cross coupling. The lower yields obtained from the cross-coupling of 2,6-dichloropurines is most likely contributed to the 2-chlorine reducing the reactivity of the 6-chlorine, or undesired cross-coupled products at the 2-position of the purine that may have resulted, but were not isolated. 3’-Fluoro-2

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• phosporus pentachloride to prepare 4-chloro-8-methoxy-5-nitroquinoline and secondly with triflate anhydride, dimethylaminopyridine, and 2,6-lutidine to prepare 8-methoxy-5-nitro-4-triflylquinoline. The Suzuki cross-coupling was carried out on both quinoline derivatives in the presence of a palladium

Synthesis of an organic-soluble π-conjugated [3]rotaxane via rotation of glucopyranose units in permethylated β-cyclodextrin

• Jun Terao,
• Yohei Konoshima,
• Akitoshi Matono,
• Hiroshi Masai,
• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2014, 10, 2800–2808, doi:10.3762/bjoc.10.297

• )porphyrin unit and two PM β-CD groups at meta position to the bromo groups. 7-O-Monotosyl PM β-CD 1 was synthesized from a native β-cyclodextrin in two steps using an established protocol [27]. Reaction of 1 with 5-bromo-2-iodophenol (2) afforded benzene-linked PM β-CD 3. The 2:1 Suzuki cross-coupling

• , we then fixed this pseudo rotaxane structure, which was only present in 50% methanol aqueous solution. The capping reaction by Suzuki cross-coupling with pinacolboron derivative 7 bearing PM α-CD as the bulky stopper group was carried out under the same hydrophilic solvent conditions as in the

• PMCDs. Scheme 4 shows the synthetic route to the precursor of PM β-CD-based insulated oligo(para-phenylene) 20. Sequential Suzuki cross-coupling of 3 with unsymmetrically protected benzene-1,4-diboronic acid derivative 18 and diiodobiphenyl gave rise to hexa(para-phenylene) derivative 20. Pseudo linked

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• Kitamura gave tetrahalide 12 in good yield on >10 g scale [25]. Suzuki cross-coupling with 12 furnished p-terphenyl 14, followed by oxidation of the methyl groups to produce diacid 15. Intramolecular Friedel–Crafts acylation then afforded 5,11-dibromo-IF-dione 11. The yields for the Sonogashira cross

A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

• J. Alexander Willms,
• Rita Beel,
• Martin L. Schmidt,
• Christian Mundt and
• Marianne Engeser

Beilstein J. Org. Chem. 2014, 10, 2027–2037, doi:10.3762/bjoc.10.211

• -bromophenol using a strategy reported by Diemer et al. [55]. Protection of the hydroxy group to yield 3 [56] was followed by Suzuki cross-coupling with commercial pyridine-4-boronic acid leading to 4. Subsequent deprotection led to 4-(pyridine-4-yl)phenol (5) (Scheme 2) [55]. The preparation of the charge

Synthesis of rigid p-terphenyl-linked carbohydrate mimetics

• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182

• mimetics; hydrogenolysis; multivalent glycosystems; 1,2-oxazines; samarium diiodide; Suzuki cross-coupling; Introduction Carbohydrates are the class of biomolecules with the highest structural diversity [1][2]. Specific carbohydrates are responsible for cell-type specific interactions [3] and they are

• successfully prepared [19]. The Suzuki cross-coupling is particularly suitable for carbohydrate chemistry due to the mild reaction conditions and its tolerance to a variety of functional groups [20]. In addition, the reactions are easy to perform and the required boronic acids exhibit exceptional stabilities

• bicyclic 1,2-oxazine derivative 3 was used as key building block for the Suzuki cross-coupling reaction to synthesize p-terphenyl-linked derivatives 1. The key intermediate 3 was prepared by a Lewis acid-induced rearrangement of 3,6-dihydro-2H-oxazine 4, that origins from a stereoselective [3 + 3

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

• Amitabh Jha,
• Ting-Yi Chou,
• Zainab ALJaroudi,
• Bobby D. Ellis and
• T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

• ]. The reaction of 2-chloroquinoline with 2-formylphenylboronic acid yielded tetracyclic isoindoloquinoline using Suzuki cross-coupling conditions where the C–C bond formation is followed by nucleophilic attack of the pyridine lone pair on the neighbouring aldehyde and proton migration [21]. Several

Molecular recognition of isomeric protonated amino acid esters monitored by ESI-mass spectrometry

• Andrea Liesenfeld and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 825–831, doi:10.3762/bjoc.10.78

• , followed by hydrolysis to afford phenol 6 which was finally transferred into the corresponding triflate 7 in 64% yield (Scheme 1). Triflate 7 was then subjected to a Sonogashira cross-coupling reaction and a Suzuki cross-coupling reaction followed by treatment with boron tribromide to obtain the

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• hexacyanoferrate then afforded diamide 24 in moderate yield [38]. Its subsequent chlorination with a mixture of phosphorous pentachloride and phosphoryl chloride furnished dichloride 25 in quantitative yield [38]. Finally, two-fold Suzuki cross-coupling of 25 with 2,6-dimethoxyphenylboronic acid (26) derived from

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

• Rainer Hovorka,
• Sophie Hytteballe,
• Torsten Piehler,
• Georg Meyer-Eppler,
• Filip Topić,
• Kari Rissanen,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

• of the racemic material was transformed into the corresponding racemic ditriflate (rac)-2 which was reacted with a 4-pyridylboronic acid ester in a Suzuki cross-coupling to afford the desired racemic bis(pyridine) ligand (rac)-3. (Please note that (rac)-3 has been prepared before, however, on a

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes

• Ludovic Eberlin,
• Fabien Tripoteau,
• François Carreaux,
• Andrew Whiting and
• Bertrand Carboni

Beilstein J. Org. Chem. 2014, 10, 237–250, doi:10.3762/bjoc.10.19

• conditions that prevent the dimerization by-product formation. These four-coordinate boron complexes participated in the same tandem Diels–Alder/Suzuki cross-coupling sequence, which appeared to be palladium- catalysed. The final cycloadducts were obtained in good yields (63% to 83%) [53]. Finally, Welker

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

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

• )-alt-5,5'-bithiophene/PS-βCD] (PDOF-BTc), was synthesized by Suzuki cross-coupling reaction between 5,5'-dibromo-2,2'-bithiophene (BT), as an inclusion complex in PS-βCD cavities, and the bulky molecule 9,9-dioctylfluorene-2,7-bis(trimethylene borate) (DOF), (Scheme 1). Of particular interest is the

• . Results and Discussion The paper describes the preparation of poly[2,7-(9,9-dioctylfluorene)-alt-5,5'-bithiophene/PS-βCD] (PDOF-BTc) main-chain polyrotaxane and its noncomplexed PDOF-BT counterpart copolymer by Suzuki cross-coupling reaction. The preparation of copolymer polyrotaxane (PDOF-BTc) involves a

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• structure analysis (Figure 3d). Moreover, a Suzuki cross-coupling reaction with boronic acid 16 gave the product 17, albeit in rather low yield (Scheme 7). The substitution was confirmed by NOESY 1D experiments (see Supporting Information File 1). Finally, we observed that upon storage at room temperature

meta-Oligoazobiphenyls – synthesis via site-selective Mills reaction and photochemical properties

• Raphael Reuter and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2012, 8, 877–883, doi:10.3762/bjoc.8.99

• the analysis of the photochemical properties. In this context we designed a novel strategy to access meta-oligoazobiphenyls via site-selective Mills reaction and Suzuki cross-coupling in a highly efficient iterative way. Photochemical examination of the resulting monomeric and oligomeric azo compounds

• example, biological settings. As a synthetic strategy it would be highly desirable to be able to build up the oligomer in a modular, protecting-group-free manner. In this respect, we planed a combination of the Mills reaction [27] with Suzuki cross-coupling, which we have successfully employed in previous

• summary, a very efficient modular synthetic approach for the preparation of meta-oligoazobiphenyls has been developed relying on a site-selective Mills reaction and Suzuki cross-coupling. The switching behavior of the azo units seems to be rather independent from an electronic point of view. However

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• moderate chemoselectivity of organozinc reagents towards substrates bearing acidic hydrogen atoms, such as N–H and O–H bonds. This is an important limitation of the Negishi cross-coupling, especially compared to the Suzuki cross-coupling based on boronic acid derivatives, which are much more tolerant

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• catalyst; Suzuki–Miyaura reaction; Introduction The formation of Csp2–Csp2 bonds has long remained a difficult task until the development of the Suzuki–Miyaura palladium-catalyzed reaction [1][2][3]. The palladium-catalyzed Suzuki cross-coupling reaction of aryl halides with arylboronic acids is one of

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• nonaflates [53], Grignard reagents with dihalobenzenes [54][55][56]: Other methods give poor yields. The Suzuki cross coupling protocol has been used for the synthesis of terphenyls and polyaryls using Pd(OAc)2 or Pd(PPh3)4 with or without ligands in homogeneous medium [57][58][59][60]. Although, these

• , and NMR. The effect of different solvents on the Suzuki coupling reactiona. The effect of various bases on the Suzuki coupling reactiona. The effect of various temperatures on the Suzuki coupling reactiona. Suzuki cross coupling reaction of aryl halides with arylboronic acida. Suzuki cross coupling

A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 53, doi:10.3762/bjoc.6.53

• inhibition nor any significant slowing of the photoreaction of the ligand was observed. Conclusion We have developed the synthesis of two highly fatigue resistant bis(terpyridinyl) diarylethenes by Suzuki cross coupling methods. The photochemical behavior of the free ligand 10a met our expectations regarding

Efficient and improved synthesis of Telmisartan

• A. Sanjeev Kumar,
• Samir Ghosh and
• G. N. Mehta

Beilstein J. Org. Chem. 2010, 6, No. 25, doi:10.3762/bjoc.6.25

• antihypertensive drug Telmisartan has been developed, featuring a Suzuki cross-coupling for the construction of the biaryl moiety and a regiospecific reductive amination-condensation sequence for the synthesis of the central benzimidazole. Experimental All solvents and reagents were purchased from the commercial

A convenient catalyst system for microwave accelerated cross- coupling of a range of aryl boronic acids with aryl chlorides

• Matthew L. Clarke,
• Marcia B. France,
• Jose A. Fuentes,
• Edward J. Milton and
• Geoffrey J. Roff

Beilstein J. Org. Chem. 2007, 3, No. 18, doi:10.1186/1860-5397-3-18

• microwave accelerated cross-coupling procedure between aryl chlorides with a range of boronic acids has been developed. An explanation for the low reactivity of highly fluorinated boronic acids in Suzuki coupling is provided. Background The Suzuki cross-coupling represents an extremely useful method for