Synthesis of three-dimensional porous hyper-crosslinked polymers via thiol–yne reaction

• Mathias Lang,
• Alexandra Schade and
• Stefan Bräse

Beilstein J. Org. Chem. 2016, 12, 2570–2576, doi:10.3762/bjoc.12.252

• monoaddition of a thiol to an alkyne. The absence of a vibration band at 2900 cm−1 reveals that there are no saturated fragments in the HCPs, again showing that only a monoaddition and no further addition to the corresponding thioacetal or 1,2-disulfide took place (Figure 1 and Figure 2). The elemental

Development of a continuous process for α-thio-β-chloroacrylamide synthesis with enhanced control of a cascade transformation

• Olga C. Dennehy,
• Valérie M. Y. Cacheux,
• Benjamin J. Deadman,
• Denis Lynch,
• Stuart G. Collins,
• Humphrey A. Moynihan and
• Anita R. Maguire

Beilstein J. Org. Chem. 2016, 12, 2511–2522, doi:10.3762/bjoc.12.246

• , NaOH, Na2CO3) and concentrations (0.1–0.3 M) were investigated using methanol as solvent (see Supporting Information File 1), however, unreacted α-chloroamide 1 and diphenyl disulfide were detected as product components in all experiments. Direct sampling of the reaction mixture (system effluents) also

• presence of diphenyl disulfide in the isolated product, the stoichiometry of thiophenol was also examined. Interestingly, a reduction in the excess of thiophenol to 1.05 equivalents was found to give a greater proportion of α-thioamide 2 and significantly reduced level of diphenyl disulfide (entries 7–13

• found to give an acceptable quality of product 2, with no detectable quantities of starting material 1 or diphenyl disulfide by HPLC analysis (entry 13, Table 1). The optimized continuous process (Scheme 6) was then run on a 5 g scale with no observed loss of yield or purity. The α-thioamide 2, which

A direct method for the N-tetraalkylation of azamacrocycles

• Andrew J. Counsell,
• Angus T. Jones,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239

• peptide-based disulfide macrocycles in a dynamic combinatorial library [49]. They observed different product distributions when reaction mixtures were shaken than when stirred, concluding that “mechanical forces can ... determine the outcome of a covalent synthesis” and that the ‘mechanosensitivity’ of

Methylenelactide: vinyl polymerization and spatial reactivity effects

• Judita Britner and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 2378–2389, doi:10.3762/bjoc.12.232

• conversion of MLA due to the impurities of thioacetic acid like disulfide and acetic acid). In this context, the iodine catalyzed thiol-Michael addition was investigated [11]. Controlled radical polymerization of MLA via RAFT Since MLA acts as a vinyl monomer, it was also interesting to evaluate the

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• feature of these compounds as it can help to remove incompletely substituted compounds (defected structures) and unused reagent as the thiolate is less stable after their basic decomposition; thiols are easy to oxidize to disulfide under basic conditions. The TU reactions (3a and 3b) in the ball mill gave

Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

• Gergely L. Tolnai,
• Jonathan P. Brand and
• Jerome Waser

Beilstein J. Org. Chem. 2016, 12, 745–749, doi:10.3762/bjoc.12.74

• efficiency of the reaction for the functionalization of proteins both in cell lysates and in the living cell was finally demonstrated [36]. Even if the alkynylation of cysteines is an important method, thiols are often part of disulfide bonds in folded proteins, and therefore difficult to access. Reduction

Optimized methods for preparation of 6^I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives

• Eva Bednářová,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2016, 12, 349–352, doi:10.3762/bjoc.12.38

• with dithiols. We also intended to use this method, but the described procedure gives only yields around 20%. The second method [13] is using a disulfide of mercaptopropionic acid which is coupled by an amide bond to two molecules of 6I-amino-β-CD to form a stable CD disulfide derivative. This

• disulfide can be used directly for functionalization of a gold surface, but its reduction to thiol was not described. In any case, the amide-containing derivative might not be stable enough under basic conditions needed for the polydopamine derivatization by the thiol. Besides, the common problem with the

• preparation of this type of sulfanyl derivatives – formation of disulfide byproducts – was not addressed in the literature at all. Therefore, we decided to develop more general procedures for the preparation of such CD derivatives and also a method for controlled preparation of corresponding disulfides, which

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• example, disulfide [10], acetal [11], imine [12] and boronates [13][14][15][16], to allow the generation of new covalent structures under thermodynamic control. Complete esterification is observed for boronate esters bearing ortho-amines [17]. The conceptual advantage compared to traditional irreversible

• reversible dynamic chemistry of specific oligomers are suitable for oligopeptides. Disulfide bonds seem to be the natural choice for the reversible covalent chemistry of peptides, but it appeared to us impossible to prevent both the template and the peptide from homo-oligomer formation. Self-aggregation is

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• comprising a γ-CD duplex system connected by two disulfide bonds that forms stable complexes with steroids appeared [19]. However, no crystal structure of any of its inclusion complexes was reported. Finally, the lack of published studies on the potential for CDs to improve the aqueous solubility of 2ME also

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• dropwise at room temperature to a solution of one equivalent of ketone 1 in dioxane, providing 2-bromo-1-([2.2]paracyclophan-4-yl)ethan-1-one (2) in 81% yield. The reactions of α-bromophenones with salts of dithiocarbamic acid, readily available from the reaction of secondary amines with carbon disulfide

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• new C–O and C–N bonds [2]. Such reactions are extensively used in practice for combining the functionality and the processability of different polymers in one material [3]. A more recent line of research is associated with dynamic covalent polymers containing alkoxyamine, imine, disulfide, and other

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• polymerization of tubulin in vitro. The same methodology might be applied to direct a drug by conjugation to a molecule binding to a specific receptor on cancer cells. Moreover, by using dicarboxylated linkers with a disulfide bridge, it was possible to generate dynamic libraries of dimeric hybrids based on

• disulfide exchange reactions in vivo [42][43]. All of these compounds were synthesized by (sometimes troublesome) chemical protocols requiring accurate control of the reaction conditions and several protection/deprotection steps. This is avoided using a biocatalyzed approach, as it has been shown exploiting

• acid dimethyl ester [56]. The obtained polymers formed supramolecular aggregates with diameters between 120 and 250 nm, which were able to encapsulate Nile red (31) that was used as a model of a drug compound (Figure 7). Copolymers containing disulfide groups in the main chain were synthesized from 3,3

Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks

• Amit M. Jabgunde,
• Alejandro Gimenez Molina,
• Pasi Virta and
• Harri Lönnberg

Beilstein J. Org. Chem. 2015, 11, 1553–1560, doi:10.3762/bjoc.11.171

• of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks is described. To obtain the building blocks, N-acyl protected 2´-deoxy-5´-O-(4,4´-dimethoxytrityl)ribonucleosides were

• -protected oligodeoxyribonucleotide trimer 3’-pTpdCBzpdGibu-5’ as its 3’-(2-chlorophenyl phosphate) was achieved by reductive cleavage of the disulfide bond. Keywords: disulfide linker; oligodeoxyribonucleotides; phosphotriester chemistry; precipitation; soluble support; Introduction Synthetic nucleic

• , the disulfide linkage may be reductively cleaved and the phosphate bound 2-mercaptoethyl group is removed. Accordingly, the oligomer expectedly is released in a fully protected form. We now report on the synthesis of such a soluble support, 3, and show that it allows efficient coupling by the 1

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

• Mohamed Yacine Ameur Messaoud,
• Ghenia Bentabed-Ababsa,
• Madani Hedidi,
• Aïcha Derdour,
• Floris Chevallier,
• Yury S. Halauko,
• Oleg A. Ivashkevich,
• Vadim E. Matulis,
• Laurent Picot,
• Valérie Thiéry,
• Thierry Roisnel,
• Vincent Dorcet and
• Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

• be employed after deproto-zincation (interception with aldehydes, phenyl disulfide and allyl bromide, or palladium-catalyzed cross-coupling with aryl halides) [35], we chose the iodolysis, which is the most efficient quench. In addition, it offers the possibility of a subsequent functionalization of

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

• Iris Binyamin,
• Shoval Meidan-Shani and
• Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

• starting materials, without isolation of intermediate 6 (Scheme 3). This method was found to be superior to two other protocols: reaction of phenyl disulfide with 3-hydroxypropyl(phenyl)phosphine oxide [30] and reaction of allyl alcohol with benzene phosphinic acid monobutyl ester in the presence of di

One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

• containing Et3N and a thick brick-red liquid was formed. Next, H2O (1 mL) and H2O2 (1.2 mmol) were added to the reaction mixture and the resulting solution was stirred for 1 h at room temperature. Extractive work-up with EtOAc followed by silica gel column chromatography afforded benzoyl disulfide in 91

New tris- and pentakis-fused donors containing extended tetrathiafulvalenes: New positive electrode materials for rechargeable batteries

• Shintaro Iwamoto,
• Yuu Inatomi,
• Daisuke Ogi,
• Satoshi Shibayama,
• Yukiko Murakami,
• Minami Kato,
• Kazuyuki Takahashi,
• Kazuyoshi Tanaka,
• Nobuhiko Hojo and
• Yohji Misaki

Beilstein J. Org. Chem. 2015, 11, 1136–1147, doi:10.3762/bjoc.11.128

• . TTP and TTPY are actually less soluble in organic solvents than TTF. In particular, TTPY is barely soluble in common solvents even in carbon disulfide. However, the maximum electrons cannot be utilized for TTP and TTPY batteries because TTP and TTPY dissolve in the electrolyte solutions in their

• cyclic voltammograms of 5d, 7d and 9d measured in a carbon disulfide/benzonitrile (1:1, v/v) solution are shown in Figure 5. As for the tris-fused donors 5d and 7d, four pairs of redox waves were observed. The peak currents of the first and second redox waves were about double those of the others. The

• of 20 and 21. Synthesis of 5–9. Plausible redox processes of 5d and 7d. Plausible redox process of 9d. Orbital energies (eV) of 5a, 6a and 8a. Redox potentials of 5d, 7d, 9d and their related compounds (V vs Fc/Fc+, in benzonitrile/carbon disulfide 1:1, v/v). Charge–discharge parameters for the

Donor–acceptor type co-crystals of arylthio-substituted tetrathiafulvalenes and fullerenes

• Xiaofeng Lu,
• Jibin Sun,
• Shangxi Zhang,
• Longfei Ma,
• Lei Liu,
• Hui Qi,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 1043–1051, doi:10.3762/bjoc.11.117

• (12.8 mg, 2 mmol) and C60 (7.2 mg, 1 mmol) were dissolved in carbon disulfide (CS2, 7 mL), and the resulting mixed solution was then placed in the dark hood and left standing without disruption. After 2 weeks, the black block-like single crystalline complex was cropped, and the composition of the

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

• Daniel Schöne,
• Boris Schade,
• Christoph Böttcher and
• Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

• nanoparticles are very similar to those for DNA. Either one part of the recognition system is directly bound to the surface of the nanoparticle by a disulfide bond and the addition of a linker induces assembly, or both linker and acceptor are immobilised on the surface of different nanoparticles and induce

Orthogonal dual-modification of proteins for the engineering of multivalent protein scaffolds

• Michaela Mühlberg,
• Michael G. Hoesl,
• Christian Kuehne,
• Jens Dernedde,
• Nediljko Budisa and
• Christian P. R. Hackenberger

Beilstein J. Org. Chem. 2015, 11, 784–791, doi:10.3762/bjoc.11.88

• canonical amino acids, particularly cysteine. For example, SPI was used to introduce a NCAA such as azidohomoalanine (Aha) in a methionine-(Met)-auxotroph in combination with the chemical modification of the natural amino acid cysteine [30][31]. These handles were, e.g., addressed by CuAAC and disulfide

• cysteine has some drawbacks including the high tendency for disulfide bond formation or cross reaction with other cysteine residues, reaction reversibility, and occasionally side-reactions with basic side chains, e.g., lysines [33]. Specifically, in the current paper we use in the current paper the oxime

Regulation of integrin and growth factor signaling in biomaterials for osteodifferentiation

• Qiang Wei,
• Theresa L. M. Pohl,
• Anja Seckinger,
• Joachim P. Spatz and
• Elisabetta A. Cavalcanti-Adam

Beilstein J. Org. Chem. 2015, 11, 773–783, doi:10.3762/bjoc.11.87

• , is highly conserved [50]. Six of the seven cysteine residues Cys14/Cys79, Cys47/Cys113, and Cys43/Cys111 form intramolecular disulfide bonds to stabilize the monomer, whereas the seventh cysteine (Cys78) contributes to the formation of an intermolecular bond between the two monomers for dimerization

• focal adhesion and actin fibers is hindered (b). Reprinted with permission from [29]. Copyright 2009 American Chemical Society. (a) BMP-2 homodimer. 3D-Structure of a BMP-2 homodimer (blue and pink) with cysteine residues, highlighted in yellow to show the intra- and intermolecular disulfide bonds

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• interference has also been described [24]. We recently reported the synthesis of a number of chiral disulfide sulfurizing reagents [25] and the results of the sulfurization of phosphite triesters in order to look for stereoselectivity [26]. In order to change such a method into a practical synthesis route for

• 16. Treatment of 16 with approximately 4 equiv of phenylacetyl disulfide (PADS) [57] gave the known dinucleoside phosphorothioate 17 [26][58]. Phosphorus epimerization. During the many attempts to purify the acyl dinucleosides by chromatography, it became apparent that some fractionation of the

Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups

• Ji-Hun Seo,
• Shino Nakagawa,
• Koichiro Hirata and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2014, 10, 2623–2629, doi:10.3762/bjoc.10.274

• (PRX) crosslinker with cleavable end groups was synthesized to develop degradable photosetting composite resins. The PRX containing 50 α-cyclodextrins (α-CDs) with disulfide end groups was initially modified with n-butylamine to obtain a resin monomer-soluble PRX. The PRX containing 13 n-butyl groups

• -soluble PRX crosslinker can be applied to design degradable photosetting plastics potentially used in the industrial or biomedical field. Keywords: α-cyclodextrin; composite resin; disulfide; polyrotaxane; Vickers hardness; Introduction Polyrotaxane (PRX) is a supermolecule containing host molecules

• ][4]. For example, if cleavable end-capping groups such as disulfide groups are introduced at both ends of PRX, the threaded α-CD molecules could be completely released by disassembling the PRX structure when a preferable stimulation such as dithiothreitol (DTT) is applied to the cleavable end-capping

Reversibly locked thionucleobase pairs in DNA to study base flipping enzymes

• Christine Beuck and
• Elmar Weinhold

Beilstein J. Org. Chem. 2014, 10, 2293–2306, doi:10.3762/bjoc.10.239

• ][45][46][47][48]. The amino-alkylthiol linker is introduced as its disulfide dimer to protect the sulfur and ensure that the reaction with the convertible nucleobase occurs via the amino group. Two of these residues are placed in adjacent base pairs and reduction of the linker disulfides frees the

• thiol groups, which, upon removal of reducing agent, react under oxidative conditions to form a disulfide cross-link. Adjacent A/A, C/C, G/G and T/T cross-links have been synthesized with this method. An interstrand G/G cross-link of adjacent G/C base pairs was used to study binding of the DNA cytosine

• thionucleosides like 2’-deoxy-6-thioinosine (dI6S) with 2’-deoxy-4-thiothymidine (dT4S) or 2’-deoxy-4-thiouridine (dU4S) via a disulfide linkage, appears to be very attractive for studying protein–DNA interactions. These thionucleosides can easily be incorporated in synthetic ODN and the linkage is formed without

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• based on an asymmetric sulfuration (route A) or asymmetric alkylation (route B) of a chiral phosphorus carbanion (Scheme 12) [36]. Deprotonation of (R,R)-28a and alkylation with 3-(3’-phenoxyphenyl)propyl iodide (96) gave 97. Sulfuration of the Li anion of 97 with tetramethylthiuram disulfide provided