Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors

• Thibault E. Schmid,
• Sammy Drissi-Amraoui,
• Christophe Crévisy,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263

• ]. Unsymmetrical bidentate hydroxyalkyl precursor L12 led to the most efficient system in the insertion of methyl groups in such architectures, being highly versatile synthetic platforms [34][35]. A wide variety of α,β-unsaturated acyl-N-methylimidazoles could thus be reacted in high yields and

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• fixation step, as well as subsequent transformations, must be harnessed efficiently. Suitable technological platforms are yet to be developed. Though there is much progress to be made before CO2 fixing enzymes may be readily used as modules in designer synthetic pathways, the rapid progress that is being

• made in the fields of genetic engineering, bioinformatics and synthetic biology, as well as renewable electricity generation and bioelectrochemical engineering hold much promise for the development of the biotechnological platforms that

Tuning the size of a redox-active tetrathiafulvalene-based self-assembled ring

• Sébastien Bivaud,
• Sébastien Goeb,
• Vincent Croué,
• Magali Allain,
• Flavia Pop and
• Marc Sallé

Beilstein J. Org. Chem. 2015, 11, 966–971, doi:10.3762/bjoc.11.108

• crystallographic data CCDC 1043205. Acknowledgements The authors gratefully acknowledge the CNRS, the Région des Pays de la Loire and the MENRT for PhD grants (SB and VC), the PIAM (Univ. Angers) and the CRMPO (Univ. Rennes) technical platforms for their assistance in spectroscopic analyses. An access to the

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• tedious and multistep syntheses using either divergent or convergent approaches are arguably the reason for their limited use as support in organic synthesis [18]. To overcome these obstacles, a hybrid dendron-polymer might constitute a valuable alternative for high-loading platforms [19], despite the use

Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• ] were converted to the corresponding triscatecholates 11 and 13 by coupling to dopamine (Scheme 2). The resulting triscatecholates 11 and 13 may be used as synthetically flexible platforms for functionalizations of surfaces via either nucleophilic addition (to the Michael acceptor in 11) or radical

• = hydroxybenzotriazole; TFA = trifluoroacetic acid, KOTMS = potassium trimethylsilanolate, DIEA = N,N-diisopropylethylamine. Synthesis of tripodal catecholate platforms 11 and 13 for surface functionalization. Supporting Information Supporting Information File 192: Experimental procedures, additional analytical data

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• trans-sialidase. Taking into consideration that mainly ester but also glycosidic linkages are labile in biological fluids, we choose amide and thioglycosidic bonds to attach the sugar residues to the platforms. 2,3,4,6-Tetra-O-acetyl-β-D-galactosylamine (1) was obtained by catalytic hydrogenation of the

Photorelease of phosphates: Mild methods for protecting phosphate derivatives

• Sanjeewa N. Senadheera,
• Abraham L. Yousef and
• Richard S. Givens

Beilstein J. Org. Chem. 2014, 10, 2038–2054, doi:10.3762/bjoc.10.212

• does not occur in aqueous acetonitrile although diethyl phosphate is released. Other substitution patterns on the naphthyl or quinolin-5-yl core, such as the 2,6-naphthyl 10 or 8-benzyloxyquinolin-5-yl 24 platforms, also do not rearrange by aryl migration upon photolysis and, therefore, do not proceed

• application in biochemistry and chemistry [15]. We now report new pHP analogs with a fused aromatic or heteroaromatic extension of pHP. Our intent was to impose the pHP motif on the naphthyl and indolin-5-yl platforms (maintaining the critical substituent pattern) in order to foster aryl ketone migration by a

Orthogonal dual thiol–chloroacetyl and thiol–ene couplings for the sequential one-pot assembly of heteroglycoclusters

• Michele Fiore,
• Gour Chand Daskhan,
• Baptiste Thomas and
• Olivier Renaudet

Beilstein J. Org. Chem. 2014, 10, 1557–1563, doi:10.3762/bjoc.10.160

• binary combinations of α-D-Man or β-D-GlcNAc, thus providing rapid access to attractive heteroglycosylated platforms for diverse biological applications. Keywords: chemoselective ligation; heteroglycocluster; multivalency; multivalent glycosystems; one-pot synthesis; Introduction Multivalent

Multichromophoric sugar for fluorescence photoswitching

• Stéphane Maisonneuve,
• Rémi Métivier,
• Pei Yu,
• Keitaro Nakatani and
• Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

• environmental saving reasons. Saccharides are polyfunctional molecules with well-defined stereogenic centres in one molecular unit, and constitute “platforms” on which multiple functional moieties can be attached. Among many applications, the use of photochemical devices based on sugar derivatives is

• "platforms". Experimental General details Commercially available solvents and reagents were used without further purification. Compounds 3 [27], 5 [25] and 9 [26] were prepared according to the literature. Melting points were measured on a Kofler bench. Optical rotations were measured using a JASCO P-2000

Synthesis of the first examples of iminosugar clusters based on cyclopeptoid cores

• Mathieu L. Lepage,
• Alessandra Meli,
• Anne Bodlenner,
• Céline Tarnus,
• Francesco De Riccardis,
• Irene Izzo and
• Philippe Compain

Beilstein J. Org. Chem. 2014, 10, 1406–1412, doi:10.3762/bjoc.10.144

• France, 103 Bd Saint-Michel, 75005 Paris, France 10.3762/bjoc.10.144 Abstract Cyclic N-propargyl α-peptoids of various sizes were prepared by way of macrocyclizations of linear N-substituted oligoglycines. These compounds were used as molecular platforms to synthesize a series of iminosugar clusters

• glycosidase inhibitor clusters published in the literature are based on these binding motifs [1][2][3][4][5][6][7][11][43] providing thus the opportunity to assess the relevance of cyclopeptoid cores by comparison with the other platforms already described. Scaffold synthesis The linear precursors of cyclic

Synthesis of a sucrose dimer with enone tether; a study on its functionalization

• Zbigniew Pakulski,
• Norbert Gajda,
• Magdalena Jawiczuk,
• Jadwiga Frelek,
• Piotr Cmoch and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2014, 10, 1246–1254, doi:10.3762/bjoc.10.124

• synthesis; sucrose; Introduction Molecular recognition is one of the most important phenomena in stereoselective processes. Chiral crown ethers (or analogs) are particularly useful in enantioselective reactions [1][2] as well as differentiation of chiral guests [3][4]. From all of the chiral platforms

Plakilactones G and H from a marine sponge. Stereochemical determination of highly flexible systems by quantitative NMR-derived interproton distances combined with quantum mechanical calculations of ¹³C chemical shifts

• Simone Di Micco,
• Angela Zampella,
• Maria Valeria D’Auria,
• Carmen Festa,
• Simona De Marino,
• Raffaele Riccio,
• Craig P. Butts and
• Giuseppe Bifulco

Beilstein J. Org. Chem. 2013, 9, 2940–2949, doi:10.3762/bjoc.9.331

• support by the University of Salerno and by Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR), PRIN 2009 “Design, conformational and configurational analysis of novel molecular platforms” is gratefully acknowledged.

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• -symmetric platforms hexahydroxytriphenylene and hexaaminotriptycene providing large and rigid molecular architectures. Because of the persistent cavities these scaffolds are very potent supramolecular affinity materials for head space analysis by quartz crystal microbalances. The scaffolds serve in

Investigating the continuous synthesis of a nicotinonitrile precursor to nevirapine

• Ashley R. Longstreet,
• Suzanne M. Opalka,
• Brian S. Campbell,
• B. Frank Gupton and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2013, 9, 2570–2578, doi:10.3762/bjoc.9.292

• [9][10][11][12]. This confluence of increased demand and cost provides an opportunity to reevaluate both the chemistry as well as the manufacturing platforms by which this drug can be produced. The two key Food and Drug Administration (FDA) registered starting materials in the commercial nevirapine

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

• corresponding alcohol 7 [44], the transfer from batch reactor operation to continuous flow processing was efficient and required little further optimization. Furthermore, we showed that methodology developed using different reaction platforms, including commercial microreactors and stainless steel continuous

• provided a good comparison of different technology platforms. If the cyclodehydration could be incorporated into a multi-step process and was spontaneous under the reaction conditions, following Michael addition to ethynyl ketones, then the continuous production of pyridines from readily-available

• [67] and under microwave irradiation [10][68][69][70][71][72]. Furthermore, this reaction has been studied in a conductive heating Uniqsis FlowSyn reactor [71][73] and its comparison with microwave heating batch experiments showed that the energy efficiency of these technology platforms vary with

Synthesis of mucin-type O-glycan probes as aminopropyl glycosides

• David Benito-Alifonso,
• Rachel A. Jones,
• Anh-Tuan Tran,
• Hannah Woodward,
• Nichola Smith and
• M. Carmen Galan

Beilstein J. Org. Chem. 2013, 9, 1867–1872, doi:10.3762/bjoc.9.218

• ][11][12][13][14] than there are available for other types of glycosides and even fewer that lead to fragments ready to be conjugated to glycoarray platforms [15]. One of the most troublesome steps in previous approaches is the synthesis of the α-glycosidic linkage between 2-acetamido-2-deoxy-D

• -galactopyranose monosaccharide and the side-chain hydroxy groups. Herein we report a convergent approach for the highly efficient synthesis of mucin type O-glycan fragments 1–7 (Figure 1) containing an α-linked 3-aminopropyl-spacer ready for covalent attachment to glycoarray platforms. Results and Discussion A

• compounds 1–7 were produced functionalized with an amine linker ready to be incorporated onto glycoarray platforms for high throughput biological screening [31]. Structure of mucin-type oligosaccharide fragments synthesized. Synthesis of glycan targets 2–4. Synthesis of disaccharide targets 5 and 6

Hypervalent iodine/TEMPO-mediated oxidation in flow systems: a fast and efficient protocol for alcohol oxidation

• Nida Ambreen,
• Ravi Kumar and
• Thomas Wirth

Beilstein J. Org. Chem. 2013, 9, 1437–1442, doi:10.3762/bjoc.9.162

• platforms to perform reactions under continuous flow rather than in batch mode has led to improvements regarding safety and sustainability. Microreactor technology can be beneficial over classical approaches in a variety of chemical reactions. Many reactions can benefit from the properties of microreactors

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

• immediately for automated decision making. Such technologies are sufficiently practical and economical to permit widespread use, not just confined to academic laboratories. With the ready availability of cheap CCD devices and computational platforms such as Arduino [73] and Raspberry Pi [74] (Figure 16), the

• tablet computers (such as the ARM-based processor found on the Raspberry Pi) allows computational platforms to be more mobile in nature and thus better suited for deployment within the synthesis laboratory environment. In a recent patent application [77] the authors disclose a device for monitoring

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• pyridine or nicotine platforms (PyOx and NicOx, respectively) [68][69]. A moderate level of enantiocontrol (up to 51 % ee) was seen in 5-exo-trig cyclization of the 3-alkenylindole 19 (n = 1) in the presence of ligands 20 and 21, to yield 22, whilst the outcome of the 6-exo-trig cyclization of indole 19 (n

Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization

• Chunhui Dai,
• Bo Liang and
• Corey R. J. Stephenson

Beilstein J. Org. Chem. 2012, 8, 986–993, doi:10.3762/bjoc.8.111

• activity, thus exemplifying their role in drug development [2][3][4][5][6][7][8]. Moreover, the challenging molecular architecture of spirooxindoles is appealing to chemists because it evokes novel synthetic strategies that address configurational demands and provides platforms for further reaction

Formation of carbohydrate-functionalised polystyrene and glass slides and their analysis by MALDI-TOF MS

• Martin J. Weissenborn,
• Johannes W. Wehner,
• Christopher J. Gray,
• Robert Šardzík,
• Claire E. Eyers,
• Thisbe K. Lindhorst and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2012, 8, 753–762, doi:10.3762/bjoc.8.86

• generally compatible with other platforms in our laboratories, such as through the formation of SAMs on gold [18] or by coupling into maleimide-functionalised surfaces in a chemoselective fashion [19]. For the initial studies two carbohydrate derivatives, 5 and 7, were synthesised. The α-D-mannoside 5 would

Synthesis of glycosylated β³-homo-threonine conjugates for mucin-like glycopeptide antigen analogues

• Florian Karch and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47

• structural modifications assuming that the conformations remain similar to those of the natural antigens. In this respect, hybrid peptides in which β3-homo-amino acids are used to strategically replace α-amino acids might be of interest as platforms for carbohydrate-based vaccines. That is because such mixed

• of the epithelial mucin MUC1 and an N-terminal non-immunogenic triethylene glycol spacer. The latter can be used for further conjugation to immunostimulants (e.g., BSA [35] or tetanus toxoid [36]) and for immobilisation onto microarray platforms [37] within functional immunological studies. The MUC1

Continuous flow based catch and release protocol for the synthesis of α-ketoesters

• Alessandro Palmieri,
• Steven V. Ley,
• Anastasios Polyzos,
• Mark Ladlow and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2009, 5, No. 23, doi:10.3762/bjoc.5.23

• effectively and cleanly bring about chemical transformations, especially in multistep mode [17][30][31][32][33][34][35][36][37]. Given the success of these concepts, it is not surprising that we would want to adapt these principles to various flow-chemical synthesis platforms to effectuate automated multistep

A divergent asymmetric approach to aza-spiropyran derivative and (1S,8aR)-1-hydroxyindolizidine

• Jian-Feng Zheng,
• Wen Chen,
• Su-Yu Huang,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2007, 3, No. 41, doi:10.1186/1860-5397-3-41

• drug for the treatment of cancer.[15] In addition, these molecules serve as platforms for testing synthetic strategies, and several asymmetric syntheses of both enantiomers of 1-hydroxyindolizidine (3) have been reported. [27][28][29][30][31][32][33][34]In continuation of our efforts in the development