A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• unit which may be further exploited in the design of small molecule based gelators. Keywords: hydrophobic interactions; organogelator; SEM; triphenylmethyl group; xerogel; Introduction Small organic molecules capable of forming gels are called low molecular weight gelators (LMWGs) [1][2][3]. These

• industrial waste water is becoming increasingly important. Conventionally, this has been achieved through the use of materials like clay, porous silica, polymers, charcoals, etc. [37]. More recently, some gels derived from low molecular weight compounds have been shown to possess the ability to absorb dyes

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• fucosides are generally α-linked across all kingdoms of life, in glycoproteins, glycolipids, bacterial lipopolysaccharides, or low-molecular weight glycoconjugates such as glycosylated natural products. β-Linked fucosides are rarely observed, for example in the bacterial polysaccharide colanic acid [39][40

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• Toru Imai Tomohiro Michitaka Akihito Hashidzume Department of Macromolecular Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan 10.3762/bjoc.12.263 Abstract Formose reactions were carried out in the presence of low molecular weight and

• out formose reactions in the presence of low molecular weight and macromolecular boronic acid compounds. Sodium phenylboronate (SPB) and a copolymer of sodium 4-vinylphenylboronate with sodium 4-styrenesulfonate (pVPB/NaSS) were used as a low molecular weight boronic acid compound and a boronic acid

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

• because of the radical stabilized by the push–pull substituents. However, with this result it has been shown that the RAFT polymerization is a successful technique for MLA to achieve (co)polymers with narrow dispersities and with almost low molecular weight. Conclusion This first detailed study on the

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• ; Introduction Nowadays great attention is paid to the use of renewable resources for obtaining fine chemicals and fuels (see numerous reviews [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]). The biorefinery of renewable lignin-carbohydrate materials affords various low-molecular weight organic

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• intensive and expensive affording only small quantities of IPNs. In 1993 Kames et al. [18] described the reaction of dinitrogen pentoxide with seventeen low molecular weight alcohols. They demonstrated that dinitrogen pentoxide reacted readily with, for example, 1-propanol, 1-hexanol, rac-2-pentanol, 1

Bifunctional catalysis

• Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1079–1080, doi:10.3762/bjoc.12.102

• Darren J. Dixon Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK, Tel: +44 (0)1865 275648; Fax: +44 (0)1865 285002 10.3762/bjoc.12.102 Keywords: bifunctional catalysis; Bifunctional catalysis concerns the use of low molecular weight, structurally defined

A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids

• Oksana S. Mikhalchenko,
• Dina V. Korchagina,
• Konstantin P. Volcho and
• Nariman F. Salakhutdinov

Beilstein J. Org. Chem. 2016, 12, 648–653, doi:10.3762/bjoc.12.64

• of an equimolar amount of BF3·Et2O to a mixture of monoterpenoid 1 and aldehyde 6a at room temperature (Table 1, entry 1) resulted, after 1 h, in the formation of a reaction mixture containing compounds 2a and 7a as the major low molecular weight products and only minor amounts of target compound 8a

Mycothiol synthesis by an anomerization reaction through endocyclic cleavage

• Shino Manabe and
• Yukishige Ito

Beilstein J. Org. Chem. 2016, 12, 328–333, doi:10.3762/bjoc.12.35

• occurrence of multiple-drug-resistant (MDR), extensive-drug-resistant (EDR), and totally drug-resistant (TDR) pathogens has increased the need for new drug candidates for treating tuberculosis. Mycothiol (MSH) 1 is the main low-molecular-weight thiol found in most actinomycetes, including Mycobacteria and

• analyses and computational calculations [11][12]. Recently, N-acyl variants of MSH homologs, such as formyl, propanoyl, and succinoyl, have been reported [13][14][15]. Gram-negative bacteria and most Eukaryotes utilize glutathione as a low-molecular-weight thiol for maintaining a reducing environment in

• the cytosol. Gram-positive bacteria including actinomycetes lack glutathione, instead, MSH is found as the major low-molecular-weight thiol. It is considered that MSH is required for maintaining a reducing intracellular environment in Gram-positive bacteria, similar to glutathione in eukaryotes and

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• studies were also consistent with the localized crystallization of α-CD/PEG pseudo-polyrotaxanes forming interchain cross-links in the hydrogel. Low molecular weight <2 kDa PEG forms crystalline precipitates in aqueous solutions in the presence of α-CD largely because multiple α-CD thread onto the PEG

• chain such that the uncomplexed portions of the PEG chains are too short for significant interchain interaction to form a water soluble network [82][86][88]. However, when a hydrophobic adamantyl group is substituted onto one end of a low molecular weight PEG chain to form amphiphilic AD-PEG, it is

• substituents and the aggregation of the α-CD complexed portions of the AD-PEG chains. Part of the interest in these low molecular weight polymer systems arises because they are able to pass through the kidney membrane [89] and are consequently of interest as components of drug-delivery systems [89][90]. A

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• emulsion; Introduction Pickering emulsions, which are emulsions stabilized by colloidal particles instead of conventional low-molecular-weight surfactants [1], are formed through the adsorption of colloidal particles at an oil–water interface to give stable emulsion droplets. Particle adsorption, which

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• molecular weight carboxylic acids are found widely in metabolism, often as their co-enzyme A esters, and they then undergo condensation reactions through enols or enolates to generate C–C bonds typified by the processes of long chain fatty acid biosynthesis. α-Fluorovinyl thioethers, illustrated in Figure 2

• functional and complementary template in enzymatic DNA synthesis [6]. We have recently begun to explore synthesis methods to prepare α-fluorovinyl thioethers, to open up the possibility of exploring this motif as a mimetic for enols and enolates of biochemically relevant thioesters. Thioesters of low

Robust bifunctional aluminium–salen catalysts for the preparation of cyclic carbonates from carbon dioxide and epoxides

• Yuri A. Rulev,
• Zalina Gugkaeva,
• Victor I. Maleev,
• Michael North and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2015, 11, 1614–1623, doi:10.3762/bjoc.11.176

• (Figure 3) was consistent with the MALDI–TOF data, showing that most of the polymer has a molecular weight between 300 and 1000 Daltons. This type of low molecular weight polycarbonate–polyol is currently attracting much interest associated with its use in sustainable polyurethanes [35]. To show the

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

• Vladimir A. Azov,
• Diana Janott,
• Dirk Schlüter and
• Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

• molecular weight aromatic derivatives 4a and 4c [22]. To explore the scope of the reaction, we decided to conduct a deeper investigation varying reaction conditions and testing different substituents on the aromatic as well as the MPTTF components of the reaction. It led to the preparation of a family of

• moieties directly attached to an aromatic calixarene backbone, we have chosen the copper-catalysed N-arylation reaction as a method for coupling of aromatic and MPTTF moieties with each other and successfully employed it for the preparation of two bis-MPTTF-calixarene conjugates, as well as two model low

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• experiment was performed by adding α-methyl-D-mannose as low molecular weight inhibitor blocking the binding sites of ConA. As a result, all probes detached from the surface and do not adhere anymore indicating that the interaction between SCPs and ConA surface was specific [15]. With regard to the SCP

Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

• Henok H. Kinfe,
• Fanuel M. Mebrahtu,
• Mandlenkosi M. Manana,
• Kagiso Madumo and
• Mokela S. Sokamisa

Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64

• defensive low molecular weight thiol [7]. 2-C-acetamide and 2-C-acetonyl carbohydrate derivatives have also been reported to serve as inhibitors of the biosynthesis of lipids [8][9] and cell surface engineering [10], respectively. The main synthetic protocols for the synthesis of 2-C-branched sugars involve

Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption

• Dominik Schmitt,
• Carolin Regenbrecht,
• Marius Hartmer,
• Florian Stecker and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 473–480, doi:10.3762/bjoc.11.53

• . Electrolysis conditions are optimized regarding reaction temperatures below 100 °C allowing operation of aqueous electrolytes in simple experimental set-up. Employing ion exchange resins gives rise to a selective removal of low molecular weight phenols from the strongly alkaline electrolyte without

• –time yield tremendously. To circumvent the common challenges in the work-up of lignin solutions (precipitation of lignin, use of excess acid and subsequent extraction of the low molecular weight products), we developed a novel and viable strategy for direct and selective removal of vanillin (1) and

• exclusion of lignin particles by application of gel type resins. Direct electrochemical degradation of lignin into low molecular weight phenolic compounds. Influence of the anode material on the electrochemical degradation of lignin.a Polymeric backbones and functionalities of the different strongly basic

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• with anti-angiogenic activity have been intensively investigated. In addition to antibodies, several low molecular weight compounds have also been chemically and pharmacologically characterized and among them, several secondary metabolites of natural origin. In anti-angiogenic strategies, natural

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• with low-molecular-weight alcohols was performed in the presence of heterogeneous catalysts, such as Au/TiO2 [98][99][100], Au/β-Ga2O3 [101], Au/polymer [102], and AuNiOx/SiO2-Al2O3-MgO [103]. In all the above-mentioned processes in the presence of heterogeneous catalysts, low-molecular-weight alcohols

Synthesis of antibacterial 1,3-diyne-linked peptoids from an Ugi-4CR/Glaser coupling approach

• Martin C. N. Brauer,
• Ricardo A. W. Neves Filho,
• Bernhard Westermann,
• Ramona Heinke and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2015, 11, 25–30, doi:10.3762/bjoc.11.4

• can be of peptidic origin [2][3]. As an example, Harran and co-workers synthesized a low-molecular weight C2-symmetric 1,3-diyne-linked peptide 1 which was able to mimic the function of Smac (second mitochondria-derived activator of caspase) protein by triggering caspase 8 activation as well as

Synthesis and characterization of pH responsive D-glucosamine based molecular gelators

• Navneet Goyal,
• Hari P. R. Mangunuru,
• Bargav Parikh,
• Sonu Shrestha and
• Guijun Wang

Beilstein J. Org. Chem. 2014, 10, 3111–3121, doi:10.3762/bjoc.10.328

• for soft biomaterials. Low molecular weight hydrogelators are especially useful for exploring biomedical applications. Previously, we found that 4,6-O-benzylidene acetal protected D-glucose and D-glucosamine are well-suited as building blocks for the construction of low molecular weight gelators. To

• enhanced the gelation tendency for many derivatives. The introduction of the additional methoxy group on the phenyl ring led to low molecular weight gelators with a higher pH responsiveness. The resulting gels were stable at neutral pH values but degraded in an acidic environment. The release profiles of

• ; naproxen; organogelator; pH responsive; self-assembly; Introduction Low molecular weight gelators (LMWGs) have drawn great attention over the past few decades due to the formation of supramolecular structures and their potential applications as advanced materials [1][2][3][4][5][6][7]. LMWGs are also

Redox active dendronized polystyrenes equipped with peripheral triarylamines

• Toshiki Nokami,
• Naoki Musya,
• Tatsuya Morofuji,
• Keiji Takeda,
• Masahiro Takumi,
• Akihiro Shimizu and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2014, 10, 3097–3103, doi:10.3762/bjoc.10.326

• almost identical to those of the fluorine analogue (13C NMR δ 194.4, 1H NMR δ 9.92) [25]. The reaction of 6 (generated on a preparative scale in CH2Cl2) with a low-molecular weight polystyrene 7a (Mn = 1,580, polydispersity index (PDI) = 1.04, 22 mg) was performed at 0 °C (Figure 3). The resulting

Preparation and evaluation of cyclodextrin polypseudorotaxane with PEGylated liposome as a sustained release drug carrier

• Kayoko Hayashida,
• Taishi Higashi,
• Daichi Kono,
• Keiichi Motoyama,
• Koki Wada and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2014, 10, 2756–2764, doi:10.3762/bjoc.10.292

• both ends of the polymer chains in PPRXs with bulky molecules results in the trapping of CDs, which in this case cannot be de-threaded from the assembly, hence giving rise to polyrotaxanes [12][13]. Recently, PPRXs and polyrotaxanes have been utilized as drug carriers for low-molecular weight drugs [14

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

• an inclusion complex of PEG with ca. 50 α-CDs. The degradation nature of C12-Bu12-MA12 was confirmed after the treatment with DTT. As shown in Figure 3, the PRX SEC signal almost disappeared, and a large intensity of low molecular weight signals was observed within 40–50 min. The low molecular weight

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

• 11.1 mL, 12.00 mL and 12.6 mL. As expected, ultrafiltration has removed a low molecular weight fraction from the sample which is eluted between 12.8 and 14.3 mL. Average molecular weights calculated within this range of retention volumes are Mn = 37000 and Mw = 42000, both in good accordance with the