Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• synthesis of 5–8 Based on the recently obtained 1,2,3-triazole-appended N-heterocycles, as promising lead compounds with efficient and selective cytostatic activities [8][9], our research groups share an interest in derivatization of target compounds by a triazole bridge [33]. Quinoline is an important

Is the tungsten(IV) complex (NEt₄)₂[WO(mnt)₂] a functional analogue of acetylene hydratase?

• Matthias Schreyer and
• Lukas Hintermann

Beilstein J. Org. Chem. 2017, 13, 2332–2339, doi:10.3762/bjoc.13.230

• reaction mixture incubated at room temperature. Derivatization of the reaction solution with 2,4-dinitrophenylhydrazine (DNPH) precipitated a yellow substance. The original report had identified the precipitate as acetaldehyde 2,4-dinitrophenylhydrazone (9) by recording a melting point (147 °C) and

• generation of 10, and the source and purification method for substrate 2 were not indicated [13]. Derivatization to 2,4-dinitrophenylhydrazones is a well-established identification method for carbonyl compounds that recommends itself for small amounts of volatile products [38][39]. However, aldehyde

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• pharmacokinetic properties of the guest molecule, such as water solubility, bioavailability and stability [6][7]. In particular, many important drugs in cancer treatment are often toxic and/or sparingly soluble or even insoluble in water. Among other methods, reversible derivatization of these drugs into CD

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

• present the development of mechanochemical procedures for PEG functionalization without the need for bulk solvents, offering a cleaner and more sustainable alternative to existing solution-based PEG procedures. The herein presented mechanochemical procedures enable rapid and solvent-free derivatization of

• ; 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

• typically require dilute conditions under inert atmosphere, warranting large amounts of solvents and time [1][19][20]. High dilution during derivatization is a requirement of solvent-based syntheses to avoid unwanted chain lengthening caused by intermolecular reactions [21]. Having in mind the vocal demands

Influence of the milling parameters on the nucleophilic substitution reaction of activated β-cyclodextrins

• László Jicsinszky,
• Kata Tuza,
• Giancarlo Cravotto,
• Andrea Porcheddu,
• Francesco Delogu and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 1893–1899, doi:10.3762/bjoc.13.184

• derivatization [8]. Although the preparation of carbohydrate-based complexes in a ball mill has been already reported [9][10][11], the use of mechanical activation for the chemical derivatization of CDs has been rather sporadic [12][13][14][15]. In this respect, it is worth noting that CDs exhibit a

• characteristic reactivity profile. Neither traditional synthetic routes nor a conventional carbohydrate activation methodology allow for CD derivatization. The major issues stem from the differing solubility of the reagents in organic solvents, meaning that high boiling polar solvents, such as DMF or DMSO, need

• the hydrolysis of the starting material. Moreover, mechanochemical activation allowed solve one of the major problems for cyclodextrin derivatization in solution. This is usually related to the very different solubilities of the reagents, thus requiring energy transfer by heating to induce reactions

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• ) Mechanochemical synthesis of the anti-epileptic drug phenytoin (41). a) K2CO3-assisted synthesis of sulfonyl (thio)ureas. b) CuCl-catalyzed solid-state synthesis of sulfonyl ureas. Two-step mechanochemical synthesis of the antidiabetic drug glibenclamide (2). Derivatization of saccharin by mechanochemical CuCl

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• biocatalyst for these transformations. Noteworthy, various acyl donors of different chain lengths were tolerated under the mechanochemical conditions. Keywords: ball milling; enzymes; esterification; lignin derivatization; mechanochemistry; Introduction Mechanochemical reactions, particularly those carried

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• derivatization of mycolactone A/B (1a,b) with a 2-naphthylboronate-based fluorogenic chemosensor (Figure 4). The latter complexes the 1,3-diol moiety proximal to the pentaene motif of the lower side chain, thus resulting in enhanced fluorescence emission intensity of the mycolactone band upon irradiation with

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• . The correct orientation of the various compounds was easily determined chemically, e.g., by derivatization of the triad photo-sensitizer with a charged group that defined which side of the molecule could insert into the hydrophobic core of the membranes [92]. However, a correct addition sequence

N-Propargylamines: versatile building blocks in the construction of thiazole cores

• S. Arshadi,
• E. Vessally,
• L. Edjlali,
• R. Hosseinzadeh-Khanmiri and
• E. Ghorbani-Kalhor

Beilstein J. Org. Chem. 2017, 13, 625–638, doi:10.3762/bjoc.13.61

• conditions (Scheme 8). The reaction tolerated a variety of functional groups such as fluoro, cyano, hydroxy, and methoxy, allowing a further derivatization of the products [90]. 3 From N-propargyl thioamides The first example of a thiazole synthesis from N-propargyl thioamides has been reported by Short and

Solid-phase enrichment and analysis of electrophilic natural products

• Frank Wesche,
• Yue He and
• Helge B. Bode

Beilstein J. Org. Chem. 2017, 13, 405–409, doi:10.3762/bjoc.13.43

• calculated mass of 3 (Figure 1) derived from the derivatization of epoxystilbene 1, an oxidized isopropylstilbene derivative from this strain. Since only a single peak could be seen within the chromatogram, we assume that the conjugate addition took place only on the less hindered position in epoxide 1

Phosphated cyclodextrins as water-soluble chiral NMR solvating agents for cationic compounds

• Cira Mollings Puentes and
• Thomas J. Wenzel

Beilstein J. Org. Chem. 2017, 13, 43–53, doi:10.3762/bjoc.13.6

• derivatization can be used to alter the solubility, binding properties of substrates, and ultimately enantioselectivity properties of the CDs. The cavity of CDs has the secondary hydroxy groups at one opening and the primary ones at the other and the opening to the cavity at the secondary side is larger than

Synthesis and evaluation of anti-oxidant and cytotoxic activities of novel 10-undecenoic acid methyl ester based lipoconjugates of phenolic acids

• Naganna Narra,
• Shiva Shanker Kaki,
• Rachapudi Badari Narayana Prasad,
• Sunil Misra,
• Koude Dhevendar,
• Venkateshwarlu Kontham and
• Padmaja V. Korlipara

Beilstein J. Org. Chem. 2017, 13, 26–32, doi:10.3762/bjoc.13.4

• vitro anti-oxidant activity against many reactive oxygen species and to protect neuronal cells against various types of oxidative damage [2][3]. To increase the effectiveness of phenolic compounds, their lipophilization has been the choice of derivatization as it provides beneficial effects of both the

• compounds [12][13]. Additionally the terminal double bond of undecenoic acid provides a reactive group for further derivatization for producing potential functional derivatives. The synthetic route followed for the synthesis of the phenolipids is shown in Scheme 1. Initially, undecenoic acid was treated

Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

• Markus Menke,
• Pardha Saradhi Peram,
• Iris Starnberger,
• Walter Hödl,
• Gregory F.M. Jongsma,
• David C. Blackburn,
• Mark-Oliver Rödel,
• Miguel Vences and
• Stefan Schulz

Beilstein J. Org. Chem. 2016, 12, 2731–2738, doi:10.3762/bjoc.12.269

• double bond can usually not be determined by analysis of their mass spectra. Positional isomers often exhibit almost identical spectra [6] and derivatization or special mass spectrometric techniques are needed to localize double bonds [7][8][9]. Because this might also be the case for macrolides [10], it

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

• success that CD derivatization has had, but its use in the removal of muscle relaxants may revolutionize surgery. It has very high affinity with curare analogues, especially rucoronium (K11 ≈ 1.8 × 107 M−1) [7], which are widely used in surgery [6]. Its everyday use has led to increasing demand and ever

• simplicity and flexibility [18][19][20][21]. While the mechanochemical manipulation of covalent bonds is hardly a brand new concept, its diffusion into carbohydrate chemistry, and particularly into CD derivatization, has been rather slow [22][23]. The ability of HEBM to favour the nucleophilic substitution

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• and natural products as well as for the mild functionalization and derivatization of diene-containing natural products [1][2][3][4][5][6][7][8][9][10]. The reversibility of this reaction plays a considerable role in both the observed regio- and stereocontrol of the nitroso Diels–Alder reaction

Potent triazine-based dehydrocondensing reagents substituted by an amido group

• Munetaka Kunishima,
• Daiki Kato,
• Nobu Kimura,
• Masanori Kitamura,
• Kohei Yamada and
• Kazuhito Hioki

Beilstein J. Org. Chem. 2016, 12, 1897–1903, doi:10.3762/bjoc.12.179

• intermediate 7 (Scheme 2). Single-crystal X-ray structure analysis, two-dimensional NMR spectroscopy, or derivatization of I–VI was performed to unambiguously determine their structures, i.e., whether the N- or O-substituted derivative was prepared from the amido anion (Supporting Information File 1). To

Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

• Golo Storch,
• Sebastian Pallmann,
• Frank Rominger and
• Oliver Trapp

Beilstein J. Org. Chem. 2016, 12, 1453–1458, doi:10.3762/bjoc.12.141

• phases [22]. However, introduction of functional groups which enable a modular derivatization approach is often hampered by long and tedious synthetic procedures. Doherty et al. reported a rhodium catalyzed double [2 + 2 + 2] cycloaddition strategy for a convergent synthesis of “NU-BIPHEP”s [23]. In this

Synthesis of 2-substituted tetraphenylenes via transition-metal-catalyzed derivatization of tetraphenylene

• Shulei Pan,
• Hang Jiang,
• Yanghui Zhang,
• Yu Zhang and
• Dushen Chen

Beilstein J. Org. Chem. 2016, 12, 1302–1308, doi:10.3762/bjoc.12.122

• tetraphenylenes through a transition-metal-catalyzed derivatization has been developed. Three types of functionalities, including OAc, X (Cl, Br, I) and carbonyl, were introduced onto tetraphenylene, which allows the easy access to a variety of monosubstituted tetraphenylenes. These reactions could accelerate

• skeleton, the methods for the synthesis of tetraphenylene derivatives via the direct derivatization of tetraphenylene are rare. More importantly, the direct derivatization of tetraphenylene would provide an efficient method for the synthesis of tetraphenylene derivatives, in particular for unsymmetrically

• substituted ones. Although direct bromination [22], nitration [22], and acetylation [45] of tetraphenylene via electrophilic aromatic substitution have been reported, it is still desirable to develop new methods for the derivatization of tetraphenylenes. Herein we report several synthetic protocols for the

NeoPHOX – a structurally tunable ligand system for asymmetric catalysis

• Jaroslav Padevět,
• Marcus G. Schrems,
• Robin Scheil and
• Andreas Pfaltz

Beilstein J. Org. Chem. 2016, 12, 1185–1195, doi:10.3762/bjoc.12.114

• . Synthetic strategy for the synthesis of the serine-derived NeoPHOX ligand. Derivatization of the 2nd generation NeoPHOX ligands and formation of their iridium complexes. Asymmetric palladium-catalyzed allylic substitution with rac-(E)-1,3-diphenylallyl acetate. Asymmetric palladium-catalyzed allylic

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• ) [45]. Unfortunately, this route was found to be less effective in terms of isolated yields and scalability. Thus, the iron-catalyzed procedure was applied and multigram quantities of 12 were readily obtained. As shown in Scheme 3, we next focused on the further derivatization of amine 12 towards

Iridium/N-heterocyclic carbene-catalyzed C–H borylation of arenes by diisopropylaminoborane

• Mamoru Tobisu,
• Takuya Igarashi and
• Naoto Chatani

Beilstein J. Org. Chem. 2016, 12, 654–661, doi:10.3762/bjoc.12.65

• chromatography over silica gel eluting with hexane/EtOAc. Product-containing fractions were concentrated in vacuo to give a pure borylated product. Catalytic C–H borylation of arenes and related reported boron sources. Scalability and derivatization. Effect of the ligand on the Ir-catalyzed borylation of 2 with

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• the spectroscopic data always refer to the mixture obtained by an incomplete fluorescent labeling and not to the fluorescent single-isomer CD derivative. The incomplete fluorescent tagging is reflected by, for example, broad NMR signals [17]. If the goal of the derivatization is the fluorescent

• fluorescent single-isomer CD [18]. If the substrate for the fluorescent labeling is a randomly substituted CD derivative, most commonly, the obtained mixture will contain fluorescently labelled and unlabeled isomers. In this work, our purpose was to develop a generic synthetic method for the derivatization of

The aminoindanol core as a key scaffold in bifunctional organocatalysts

• Isaac G. Sonsona,
• Eugenia Marqués-López and
• Raquel P. Herrera

Beilstein J. Org. Chem. 2016, 12, 505–523, doi:10.3762/bjoc.12.50

• derivatization. Thus, in the last decade, it has been widely employed in the field of asymmetric catalysis. Regarding the use of aminoindanol derivatives as ligands in organometallic catalytic complexes, the results have been outstanding. Examples are found in (a) the vanadium-catalyzed asymmetric oxidation of

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

• 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

• obtained alkylene derivative 5g had a low solubility in water and water/alcohol mixtures what represented quite an obstacle for the intended use – derivatization of solid surfaces by treatment with the water solution of the CD derivative. Therefore, we decided also to prepare the derivatives containing the