Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

• Muhammad Israr Changqing Ye Munira Taj Muhammad Yajun Li Hongli Bao Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Center for Excellence in Molecular Synthesis, Chinese

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• catalyst and carbohydrate or small polyethylene glycol (PEG) groups were attached [11]. As another strategy to modify a protein surface with olefin metathesis, Isarov and Pokorski introduced a Grubbs 3rd generation catalyst on the surface of lysozyme and performed ring-opening metathesis polymerization

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• [15]. The ee of propylene glycol, which was obtained after hydrolysis of the copolymer obtained with (S)-PO and PA, was found to be 88%, indicating a high level of regioregularity. Molecular weight distributions are relatively narrow, while a bimodal distribution was observed in the SEC traces. The

• ). The solvents were removed under reduced pressure and Et2O (5 mL) was added to the resulting powder. After stirring for 10 min, the slurry was filtrated off and the resulting filtrate was concentrated under reduced pressure to give propylene glycol. A flame-dried flask was charged with the obtained

• propylene glycol (26 mg, 0.34 mmol), 4-(dimethylamino)pyridine (8 mg, 0.07 mmol), trimethylamine (70 µL, 0.7 mmol), and CH2Cl2 (3.4 mL). Benzoyl chloride (39 µL, 0.34 mmol) was added dropwise to the solution with stirring. After stirring at room temperature for 25 min, the reaction mixture was poured into

The design and synthesis of an antibacterial phenothiazine–siderophore conjugate

• Abed Tarapdar,
• James K. S. Norris,
• Oliver Sampson,
• Galina Mukamolova and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2018, 14, 2646–2650, doi:10.3762/bjoc.14.242

• -cleavable linker. A polyethylene glycol (PEG) linker was selected as PEG linkers demonstrate enhanced water solubility in comparison to alkyl chain linkers. We then had to make a decision on the position of attachment for the PEG linker to compound 1. For siderophore conjugates, it is crucial that the

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• TTFs. However, also the type of substituent on the TTF moiety plays a role in terms of weak secondary binding interactions such as hydrogen bonds [63]. For example TTF 5 which is substituted by ethylene glycol chains displays a high association constant of Ka = 50,000 M−1 in acetonitrile. Additionally

Efficient catenane synthesis by cucurbit[6]uril-mediated azide–alkyne cycloaddition

• Antony Wing Hung Ng,
• Chi-Chung Yee,
• Kai Wang and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2018, 14, 1846–1853, doi:10.3762/bjoc.14.158

• other topological isomers. The building blocks contain either a central hexaethylene glycol (HEG) unit or are derived from 1,5-dioxynaphthalene (DN), naphthalenediimide (NDI), 2,9-phenanthroline (Phen) or 4,4’-biphenyl (BP) cores which can engage in additional non-covalent interactions, such as metal

• of [3]catenanes The CBAAC-mediated [3]catenane synthesis was first investigated using the dioxynaphthalene building blocks DN-N3 and DN-CC. Different from the previously reported [3]catenane Cat-0 which is derived from DN-N3 and Phen-CC [24], both DN-N3 and DN-CC contain the flexible ethylene glycol

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• pathway for the synthesis of the naturally occurring antibiotic platensimycin (154) which is isolated from Streptomyces platensis. In this report, 6-methoxy-1,4-naphthoquinone-4-ethylene ketal (153) was synthesized by intermolecular oxidative cyclization of 7-methoxy-α-naphthol (152) with ethylene glycol

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• electron-poor anilines afford better results than their electron-rich congeners, while a hindered amine (t-BuNH2) completely inhibits the reaction. Shortly after, a similar synthesis of carbazoles involving Cu(OAc)2 as the catalyst in the presence of ethylene glycol both as a ligand and the co-solvent has

Spectroelectrochemical studies on the effect of cations in the alkaline glycerol oxidation reaction over carbon nanotube-supported Pd nanoparticles

• Dennis Hiltrop,
• Steffen Cychy,
• Karina Elumeeva,
• Wolfgang Schuhmann and
• Martin Muhler

Beilstein J. Org. Chem. 2018, 14, 1428–1435, doi:10.3762/bjoc.14.120

• glycol electrooxidation. For glycerol, a similar study was conducted by Ferreira et al. [14] on PdRh electrodeposits showing that the glycerol oxidation route follows a pathway involving the consumption rather than production of H2O once the initially present OH− ions are consumed. Finally, the

• influence on the water electrolysis on Pt(111) [28] and Ir(111)/oxide electrodes [29]. Different Pt single crystal surfaces [30] and other electrochemical reactions such as CO [30], formate [31] and ethylene glycol oxidation [32][33] were studied as well. Especially for these more complex oxidation

• reactions of small organic molecules, studies of the cation impact on the formed products are rather scarce. Sitta et al. [32] revealed an analogous trend as Strmcnik et al. [24], i.e., increasing current densities for ethylene glycol electrooxidation over Pt in the order Li+ < Na+ < K+. They used IR

Novel unit B cryptophycin analogues as payloads for targeted therapy

• Eduard Figueras,
• Adina Borbély,
• Mohamed Ismail,
• Marcel Frese and
• Norbert Sewald

Beilstein J. Org. Chem. 2018, 14, 1281–1286, doi:10.3762/bjoc.14.109

• glycol spacer with a terminal azide results in a complete loss of activity. Docking studies of the novel cryptophycin analogues to β-tubulin provided a rationale for the observed cytotoxicities. Keywords: cryptophycin; cytotoxic agents; novel payloads; tubulin inhibitors; tumour targeting; Introduction

• ]. Based on this, we designed cryptophycin analogues modified in the unit B. Instead of the O-methyl group that is present in the natural cryptophycin, we attached a hydroxyethyl group or a triethylene glycol chain terminated with an alcohol or azide, respectively. These functional groups would allow the

• preparation of the two different spacers that were later connected to the phenol. Starting from triethylene glycol (3) or 2-allyloxyethanol (7) tosylations and nucleophilic displacements by azide or iodide substitution provided 6 and 9 in good yields. O-Alkylation of Boc-protected 3-chlorinated D-tyrosine 10

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• synthesis and cycloaddition of tropone ethylene acetal and benzotropone ethylene acetal 157 (Scheme 27) [133]. The ketal 157 was prepared from the reaction of 4,5-benzotropone (11) with ethylene glycol in the presence of triethyloxonium tetrafluoroborate. The cycloaddition of 157 with 4-phenyl-1,2,4

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• between heteroaryl bromides, chlorides or iodides and carbamate, sulfonamide or urea derivatives to be successfully realized in water using palladium-loaded TPGS-750-M (dl-α-tocopherol methoxypolyethylene glycol succinate) micelles (Scheme 1). Moreover, this micellar catalytic system allowed for catalyst

• for facile tuning of their properties such as size [13][74], membrane permeability [75] and stability [76]. Various copolymers have been reported for polymersome formation such as poly(ethylene glycol)-b-polystyrene (PEG-b-PS) [14][77], polystyrene-b-polyisocyanopeptide (PS-b-PIAT)[21][22] and poly(N

• (X = I or Br) in water [100]. Other examples of water-soluble dendrimers are peptide- and glycol-based dendrimers [102][103]. As a result of their compositional versatility, they have been reported in many applications for biomedical engineering (e.g., glycopeptide dendrimers for drug delivery [104

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• using NaBH4 as reducing agent in a water-in-oil (w/o) microemulsion in the presence of polyethylene glycol hexadecyl ether, Brij@30 as capping agent and n-heptane as organic solvent (water/Brij@30/n-heptane). After precipitation and copiously washing with acetone and water, Pd nanoparticles were

Preparation of trinucleotide phosphoramidites as synthons for the synthesis of gene libraries

• Ruth Suchsland,
• Bettina Appel and
• Sabine Müller

Beilstein J. Org. Chem. 2018, 14, 397–406, doi:10.3762/bjoc.14.28

• of the desired products [34][39]. 4. Preparation of trinucleotides on soluble supports Another strategy of combining the advantages of solution chemistry and solid-phase methods is the assembly of oligonucleotides on soluble supports. Among the supports used for this purpose, polyethylene glycol (PEG

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• reaction of 5-aminopyrazole derivative 46, arylaldehydes 47 and cyclic ketones 48 in various solvents like acetonitrile, ethylene glycol, acetic acid, DMF under MW conditions at 80 °C (Scheme 9). The best results (72–80% yields) were obtained by carrying out the reaction in acetic acid with the addition of

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• . The yellow area depicts the range possible if each netropsin molecule overwinds the DNA as stated in previous literature. Synthesis of the tricyclic cytosine aromatic core [39]. (a) Ethylene glycol, K2CO3, 120 °C, 1 h, 40%; (b) EtOH, 1 M HCl, reflux, 16 h, 75%. Synthesis of protected tC and tCO

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• compounds using labeling reagents having a hydrazide group. A hydrophilic fluorescence group Alexa Fluor 568 and polyethylene glycol-linked biotin were introduced using hydrazone formation reaction between the aldehyde group of the glutaryl-Glc linker and the hydrazide group of the labeling reagent. In

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• substitution by reaction with NaN3 then resulted in AuNPs with mixed monolayers containing 52% N3- and 44% CH3-terminated alkanethiol ligands. A series of alkynes were synthesised, including derivatives of nitrobenzene (1), ferrocene (2), anthracene (3), pyrene (4), aniline (5), and polyethylene glycol (6) all

• synthesized in two steps (Scheme 5). Herein, the treatment of methyl-terminated triethylene glycol monolayer-protected AuNPs (Me-EG3-AuNPs) with ω-carboxy tetraethylene glycol thiols (HOOC-EG4-SH) gave carboxy-functionalized AuNPs (HOOC-EG4-AuNPs). Peptide coupling of these HOOC-EG4-AuNPs with a DBCO-amine

• solution of tetraethylene glycol–thiol (dilutor ligands), to produce particles decorated with cyclooctynes (Scheme 12). These AuNPs then underwent SPAAC when an aqueous solution of a mannose-derived azide was added, to produce mannose-functionalized GAuNPs (Scheme 12). In the presence of the mannose

Microfluidic radiosynthesis of [¹⁸F]FEMPT, a high affinity PET radiotracer for imaging serotonin receptors

• Thomas Lee Collier,
• Steven H. Liang,
• J. John Mann,
• Neil Vasdev and
• J. S. Dileep Kumar

Beilstein J. Org. Chem. 2017, 13, 2922–2927, doi:10.3762/bjoc.13.285

• ratios between the [18F]fluoride and the ditosylate precursor 9, the minimum concentration of the ditosylate precursor could be rapidly determined (Figure 2B). The reaction of [18F]TEAF with ethylene glycol ditosylate (4 mg/mL, 10 µmol/mL) in DMSO in the first reactor resulted in a final solution

Synthetic mRNA capping

• Fabian Muttach,
• Nils Muthmann and
• Andrea Rentmeister

Beilstein J. Org. Chem. 2017, 13, 2819–2832, doi:10.3762/bjoc.13.274

• via IVT. The respective U1snRNAs with a pyrophosphate bridged TMG cap and a TMG cap containing an ethylene glycol linkage were also produced [114]. Unlike IVT, solid-phase synthesis offers the flexibility to introduce modified nucleotides at specific positions. Chemical synthesis of the intricate

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• with triethylene glycol was compared (Table 4). The yield of the substitution reaction of H-subPc was only 5%, and the reaction did not proceed in the case of F-subPc. On the other hand, in TFEO-subPc, the substitution reaction at the axial position proceeded successfully, and the target substitution

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

• Leonid S. Kikot',
• Catherine Yu. Kulygina,
• Alexander Yu. Lyapunov,
• Svetlana V. Shishkina,
• Roman I. Zubatyuk,
• Tatiana Yu. Bogaschenko and
• Tatiana I. Kirichenko

Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203

• . Substitution of the methyl group in the 7 by ethylene or diethylene glycol fragments leads to an increase in stability of the complexes except 5@8 and 5@9 (Figure 5). The complex stabilities of the clips 1–3 with paraquat derivative 10 are similar compared to complexes with paraquat (7) (1@10) or slightly

Solid-state mechanochemical ω-functionalization of poly(ethylene glycol)

• Michael Y. Malca,
• Pierre-Olivier Ferko,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2017, 13, 1963–1968, doi:10.3762/bjoc.13.191

• Michael Y. Malca Pierre-Olivier Ferko Tomislav Friscic Audrey Moores Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A 0B8, Canada 10.3762/bjoc.13.191 Abstract Poly(ethylene glycol) (PEG) is a linear polymer with a wide range of applications in chemical

• PEG with tosyl, bromide, thiol, carboxylic acid or amine functionalities in good to quantitative yields and with no polymer chain oligomerization, proving the versatility of the method. Keywords: amination; bromination; carboxylation; mechanochemistry; poly(ethylene glycol); solid state; thiolation

• ; tosylation; Introduction Poly(ethylene glycol) (PEG) is a linear polyether polymer with highly hydrophilic properties. Whereas PEG functionalization is restricted to its terminal functionalities, derivatization of these sites is essential for its use in pharmaceutical and material design. Specifically

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• activity in Mizoroki–Heck reactions with DMF as solvent [66]. With this regards, we herein report the development of a new poly(ethylene glycol, PEG) and pyridine bi-functionalized imidazolium salt L1 (Figure 1), which was employed as a water soluble NHC ligand precursor for an in situ generated Pd–NHC