A macrolactonization approach to the total synthesis of the antimicrobial cyclic depsipeptide LI-F04a and diastereoisomeric analogues

• James R. Cochrane,
• Dong Hee Yoon,
• Christopher S. P. McErlean and
• Katrina A. Jolliffe

Beilstein J. Org. Chem. 2012, 8, 1344–1351, doi:10.3762/bjoc.8.154

• difficult to determine structure–activity relationships [7][8]. More recently, the solid-phase synthesis of a number of analogues of the fusaricidins has been reported. However, in all cases, the side chain 3-hydroxy group was not incorporated into the structure [9]. By total synthesis of both side-chain

Photochemistry with laser radiation in condensed phase using miniaturized photoreactors

• Elke Bremus-Köbberling,
• Arnold Gillner,
• Frank Avemaria,
• Céline Réthoré and
• Stefan Bräse

Beilstein J. Org. Chem. 2012, 8, 1213–1218, doi:10.3762/bjoc.8.135

• ), power control, flow 26 mL/h. Test setup with continuously operating, miniaturized photoreactor. The miniaturized photoreactor (PEEK) during photolysis. Synthesis of carbazole (2) by photolysis. Synthesis of arylazides 2 by solid-phase synthesis. Supporting Information Supporting Information File 370

Parallel solid-phase synthesis of diaryltriazoles

• Matthias Wrobel,
• Jeffrey Aubé and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 1027–1036, doi:10.3762/bjoc.8.115

• Biology Center, 2121 Simons Drive, West Campus, Lawrence, KS 66047, USA 10.3762/bjoc.8.115 Abstract A series of substituted diaryltriazoles was prepared by a solid-phase-synthesis protocol using a modified Wang resin. The copper(I)- or ruthenium(II)-catalyzed 1,3-cycloaddition on the polymer bead allowed

• protein–protein interactions. Keywords: chemical diversity; Huisgen cycloaddition; library synthesis; peptidomimetics; solid phase synthesis; triazole; Introduction The α-helix was the first-described secondary structure of peptides discovered by Linus Pauling in 1951 [1]. With about 30% of the amino

• potential inhibitors of protein–protein interactions. Results and Discussion Synthesis of azide-functionalized Wang resins Two azide-functionalized resins were prepared for the solid-phase synthesis of diaryl-triazoles. The commercially available 4-(bromomethyl)benzoic acid (5) was converted into azide 6 in

Multistep organic synthesis of modular photosystems

• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2012, 8, 897–904, doi:10.3762/bjoc.8.102

• substitution of the mixed cNDI 46 and deprotection of the red cNDI 47 gave the desired aldehyde 6. Self-organizing surface-initiated polymerization With the five building blocks 2–6 in hand, the solid-phase synthesis of photosystem 1 on ITO surfaces could be launched. ITO was first cleaned with RCA solution

• structures (Scheme 4 and Scheme 5). We thus summarize both processes in schematic form (Scheme 6). To recapitulate briefly from this perspective, we repeat that the solid-phase synthesis begins with the deposition of initiator 2 on ITO. Activation of monolayer 48 with DTT produces monolayer 49 with free

Building photoswitchable 3,4'-AMPB peptides: Probing chemical ligation methods with reducible azobenzene thioesters

• Gehad Zeyat and
• Karola Rück-Braun

Beilstein J. Org. Chem. 2012, 8, 890–896, doi:10.3762/bjoc.8.101

• for the application in ligation studies. AMPB = (aminomethylphenylazo)benzoic acid. Structure of the glycine-linked auxiliary conjugates 7 and 8. Structural differences between the trans- and the cis-state of azopeptides with a SKV PDZ binding motif. Solid-phase synthesis of the ligation-mediating

Synthetic glycopeptides and glycoproteins with applications in biological research

• Ulrika Westerlind

Beilstein J. Org. Chem. 2012, 8, 804–818, doi:10.3762/bjoc.8.90

• with a Pam3Cys TLR2 ligand connected to TN, T and sialyl-T MUC1 glycopeptides was recently described (Scheme 2) [35]. The Pam3CSK4 lipopeptide fragment 13 was prepared by Fmoc solid-phase synthesis, including protected amino-acid side chains after resin cleavage. Subsequently, different TN, T and

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

• Raheleh Rezaei Araghi,
• Carsten C. Mahrenholz,
• Rudolf Volkmer and
• Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

• solid-phase synthesis (0.05 mM scale) using a SyroXP-I peptide synthesizer (MultiSyn Tech GmbH, Witten, Germany) and HOBT/TBTU activation. Manual coupling of β- and γ-amino acids was carried out by HOAT/DIC activation. The molar excess of amino acid and coupling reagents was reduced for β- and γ

Planar-bilayer activities of linear oligoester bolaamphiphiles

• Jonathan K. W. Chui,
• Thomas M. Fyles and
• Horace Luong

Beilstein J. Org. Chem. 2011, 7, 1562–1569, doi:10.3762/bjoc.7.184

• Discussion Synthesis of new compounds The solid-phase synthesis of the alkyl oligoesters was previously reported [14]. The phthalate compounds were prepared by a modular methodology (Scheme 2), beginning by reacting terephthaloyl chloride or compound 9 (prepared by a method adapted from [15]) with α,ω

Synthesis, reactivity and biological activity of 5-alkoxymethyluracil analogues

• Lucie Brulikova and
• Jan Hlavac

Beilstein J. Org. Chem. 2011, 7, 678–698, doi:10.3762/bjoc.7.80

• the 3',5'-hydroxyl groups, the 5'-hydroxyl group was dimethoxytritylated and the 3'-hydroxyl group phosphitylated to afford phosphoramidite 134. The final phosphoramidite 134 was incorporated into oligodeoxynucleotide sequences via solid-phase synthesis by an automated DNA synthesizer. Modified

• protection groups at the sugar ring were removed by the reaction with TBAF. Finally, the 5'-hydroxyl groups were tritylated and the 3'-hydroxy group converted to the corresponding phosphoramidite 150. The resulting phosphoramidite was incorporated into a 12-mer oligodeoxynucleotide via automated solid-phase

• synthesis. Synthesis of bis heterocyclic derivatives Sarfati and co-workers published an interesting and facile synthesis of C-5 alkylated 2'-deoxyuridine and uridine derivatives [40]. The C-5 position can be substituted by glycosides of either 2-acetamido-2-deoxy-β-D-glucopyranose or α-D-mannopyranose. All

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• 20 on treatment with 5% HCl in ethanol underwent cyclization to afford 21. A novel solid phase synthesis of some 5-aminopyrazoles 24 and their N-acyl and N-sulfonyl derivatives has recently been reported by Watson et al. [38] via the resin supported β-ketonitriles 22 (Scheme 7). The resin supported

• aminopyrazoles 23 were hydrolysed to yield 24 in excellent yields. The synthesis is versatile and affords compoundswith a known pharmacophoric template ideally suited for combinatorial library generation. Another solid phase synthesis of 5-aminopyrazoles has been reported [39] by utilizing enamine nitrile 25 as

• -component, two-step “catch and release” solid-phase synthesis of 3,4,5-trisubstituted pyrazoles was reported which involved a base-promoted condensation of a 2-sulfonyl- or a 2-carbonyl-acetonitrile derivative (29 or 33) with an isothiocyanate and in situ immobilization of the resulting thiolate anion (30

A new and facile synthetic approach to substituted 2-thioxoquinazolin-4-ones by the annulation of a pyrimidine derivative

• Nimalini D. Moirangthem and
• Warjeet S. Laitonjam

Beilstein J. Org. Chem. 2010, 6, 1056–1060, doi:10.3762/bjoc.6.120

• -one libraries by solid-phase synthesis has been reported [19][20][21]. There are two approaches for the solution-phase parallel synthesis of 2-thioxoquinazolin-4-ones [22]. The first approach is based on the reaction of methyl anthranilates with isothiocyanates in refluxing pyridine or DMF. The second

Functionalized polymers: synthesis and properties

• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, No. 55, doi:10.3762/bjoc.6.55

• chromatography), for membranes and in the solid phase synthesis of peptides and oligonucleotides. Focusing on the constantly developing medical field, only specifically elaborated functional polymer materials can fulfill the specific challenges required of them for use as, for example, surgical sutures, dental

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

• increased biological half-life. Keywords: glycopeptide; glycosylamino acids; β3-homo-threonine; MUC1 antigens; solid-phase synthesis; Introduction Glycosylation is the predominant co- and post-translational modification in higher organisms responsible for tailoring and fine-tuning of the activity of

• remarks: DMF (amine-free, for peptide synthesis) and NMP were purchased from Roth and Ac2O in p.a. quality from Acros. Fmoc-protected amino acids were purchased from Orpegen Pharma. For solid-phase synthesis, pre-loaded TentaGel S resin (Rapp Polymere) was employed. Reactions were monitored by TLC with

• antigens and the targeted Fmoc-β3hThr analogues. Synthesis of Fmoc-β3hThr antigen conjugates by Arndt–Eistert homologation. Solid-phase synthesis of the tumour-associated MUC1 α/β-hybrid glycopeptide analogue 8 carrying the TN antigen glycan. NMP = N-methylpyrrolidone, HBTU = O-(1H-benzotriazol-1-yl)-N,N,N

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• proteins [5][6][7], cell–cell communication [8] and immune response to pathogens [7][9][10][11]. However, the application of oligosaccharides as potential therapeutic agents has its main drawback in the low instability of natural carbohydrates in biological systems. In addition, solid phase synthesis of

• hexamer adopted a repeating β-turn structure [51] dictated by internal 10-membered hydrogen bonded rings. Such conformations are similar to those reported for the δ-2,5-cis-oxetane-THF oligomers [37]. D’Onofrio et al. [52] have carried out solid phase synthesis of oligonucleotides conjugated at the 3

• inclusion complexes with aromatic guest molecules [54] and Cu(II) ion [56]. Additionally, van Well et al. have described a cyclization/cleavage strategy for solid phase synthesis of cyclic trimers and tetramers containing pyranoid δ-SAAs (Scheme 2) and reported their structural analysis from ROESY data in

Synthesis of mesogenic phthalocyanine-C₆₀ donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

• Yves Henri Geerts,
• Olivier Debever,
• Claire Amato and
• Sergey Sergeyev

Beilstein J. Org. Chem. 2009, 5, No. 49, doi:10.3762/bjoc.5.49

• expansion of subphthalocyanines or solid-phase synthesis on polymer supports [48]. However, operationally simplest and shortest route is the statistical condensation of the two different phthalonitriles. This method inevitably produces a mixture of the desired A3B phthalocyanines with the products of

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed. Keywords: asymmetric catalysis; biocatalysis; continuous flow; microreactors; solid phase synthesis; Introduction While many technological advancements have been made over

Silica- bound benzoyl chloride mediated the solid- phase synthesis of 4H-3,1-benzoxazin- 4-ones

• Kurosh Rad-Moghadam and
• Somayeh Rouhi

Beilstein J. Org. Chem. 2009, 5, No. 13, doi:10.3762/bjoc.5.13

• Kurosh Rad-Moghadam Somayeh Rouhi Chemistry Department, University of Guilan, P.O. Box 41335-19141, Rasht, Iran 10.3762/bjoc.5.13 Abstract The solid-phase synthesis of 4H-3,1-benzoxazin-4-ones was achieved using silica-bound benzoyl chloride (SBBC) as dehydrating agent in reaction with 2

• -acylaminobenzoic acids. The silica-grafted reagent (SBBC) was simply recovered after reaction and reused several times. Keywords: 4H-3,1-benzoxazin-4-one; silica-bound benzoyl chloride; solid-phase synthesis; Introduction Solid-phase approaches are gaining more and more applications in organic synthesis mainly

• because reactions with a loaded substrate can be manually sequenced and driven to higher yields by using excess reagents, which are subsequently removed by simple filtration [1][2][3][4][5][6][7]. Conventionally, solid-phase synthesis referred to approaches in which the substrate was loaded onto the solid

The first preparative solution phase synthesis of melanotan II

• Vladimir V. Ryakhovsky,
• Georgy A. Khachiyan,
• Nina F. Kosovova,
• Elena F. Isamiddinova and
• Andrey S. Ivanov

Beilstein J. Org. Chem. 2008, 4, No. 39, doi:10.3762/bjoc.4.39

• and Discussion To date, several accounts of solid phase synthesis of peptide 2 have been reported. A representative one, reported by Hruby and co-workers, exploited p-methylbenzhydrylamine resin (pMBHA) as the solid support and tert-butyloxycarbonyl (Boc) tactics for temporary protection of α-amino

A practical synthesis of the ¹³C/¹⁵N- labelled tripeptide N-formyl- Met-Leu-Phe, useful as a reference in solid- state NMR spectroscopy

• Sven T. Breitung,
• Jakob J. Lopez,
• Gerd Dürner,
• Clemens Glaubitz,
• Michael W. Göbel and
• Marcel Suhartono

Beilstein J. Org. Chem. 2008, 4, No. 35, doi:10.3762/bjoc.4.35

• cleavage process, EDT and TIS were added as scavengers [23][24]. Conclusion Compared to the solution phase synthesis of peptides, the solid phase synthesis offers a simplified purification of the intermediates. With the improved synthetic protocol based on Fmoc building blocks, where all reaction steps