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

• (Figure 1). Some examples of these properties are rigidity, disposition of the two stereogenic centers, ability of the hydroxy and amino groups to coordinate to some metals or to act as hydrogen-bond donors/acceptors, the different catalytic activity of these chemical groups and their possible

• amino groups. Although the aminoindanol scaffold appears in the structure of different catalysts (providing a suitable way to induce chirality), it is not always directly involved in the bifunctional activation of the substrates [17]. Herein, we show only those cases where the aminoindanol moiety

• confers bifunctionality to the organocatalysts, interacting with the reactants through both the hydroxy and amino groups. Review Bifunctional hydrogen-bonding-based organocatalysts Most of the examples of bifunctional aminoindanol-containing organocatalysts present in literature correspond to catalysts

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• studied for binding Gd(III) chelates that bear hydrophobic substituents and negative charges [35]. These bio-polymers were easily prepared in two reaction steps by reacting CDs with maleic anhydride followed by activation with carbodiimide to form amide linkages with amino groups of chitosan. The

Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC)

• Helmut Ritter,
• Monir Tabatabai and
• Markus Herrmann

Beilstein J. Org. Chem. 2016, 12, 245–252, doi:10.3762/bjoc.12.26

• -BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by 1H NMR

• polymerization; (meth)acryl polymers; neighboring group effects; solvent polarity; Introduction Amino groups are important functionalities in polymer chemistry, e.g., for hardening various epoxy resins [1]. However, they easily react in an undesired side reaction with electron-poor double bonds of (meth

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• sequestration. However, 27 did not appear to enter cells easily and was poorly soluble and cytotoxic. Amin Jahromi recognized that acridine-containing compounds had been previously induced to enter cells and cell nuclei by attaching amino groups that take advantage of a polyamine transporting system [84][85

Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines

• Brett N. Hemric and
• Qiu Wang

Beilstein J. Org. Chem. 2016, 12, 22–28, doi:10.3762/bjoc.12.4

• class of molecules is highly valued. Toward this end, intermolecular olefin oxyamination allows for direct and modular installation of both oxygen and amino groups to readily available olefins in a single step, representing a powerful and appealing approach over multistep sequences [7][8][9]. Sharpless

• of 1,2-oxyamino products. For example, most oxyamination methods are limited to the installation of amide or sulfonamide derivatives. The direct installation of electron-rich amino groups, especially tertiary cyclic amines, remains an unsolved problem. Furthermore, most methods employ inflexible

• associated with adding two different nucleophiles and simultaneously eliminates the need for an external oxidant. Particularly advantageous is the direct addition of electron-rich amino groups, especially tertiary amines, which are difficult to access by other known methods. Furthermore, O-acylhydroxylamines

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

• Svetlana P. Panchenko,
• Alexei D. Averin,
• Maksim V. Anokhin,
• Olga A. Maloshitskaya and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250

• group of Beletskaya [24][25][26][27]. It has been shown that the secondary dialkylamino groups in linear polyamines are practically inert and this allows a selective arylation of terminal primary amino groups. The exchange of expensive palladium accompanied with toxic ligands for a much cheaper copper

• diamines 3 and 4 we managed to isolate N,N’-diaryl derivatives 38 and 40, though their yields were too small (10 and 18%, respectively), the main products being N-(2-fluorophenyl) diamines 39 and 41. N,N’-Diarylation of tri- and tetraamines Arylation of two primary amino groups in polyamines under Cu(I

• secondary amino groups in the tetraamines 7 and 8 (Scheme 6, Table 5) led to a loss in the selectivity of the process, made chromatographic isolation more tedious and less efficient, and also diminished the catalytic activity of copper due to better coordination of the cation by four nitrogen atoms which

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• , Japan), and lyophilized to obtain Lac-β-CyD. The reaction was monitored by TLC (silica gel F254, Merck, Whitehouse Station, NJ). Eluent: methanol/water 9:1 (v/v), indicator: p-anisaldehyde for sugar and ninhydrin for amino groups. The Lac-β-CyD gave 1H NMR spectra consisting of protons of both β-CyD and

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• catalyst 5 bearing the pH-responsive H2ITap [1,3-bis(N’,N’,2’,6’-tetramethylaminophenyl)-4,5-dihydroimidazol-2-ylidene] ligand containing two NMe2 groups [61]. The addition of HCl to complex 5 results in the protonation of the amino groups to produce a water-soluble dicationic complex. Although the

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• porphyrins 7a and 7b. The IR spectra of the compounds containing amino groups showed a NH2 bond stretching band between 3348–3433 cm−1, whereas all the free-base porphyrins showed absorptions between 3322–3327 cm−1 due to the internal NH groups of the porphyrin core. In addition, a strong band was observed

An intramolecular C–N cross-coupling of β-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis

• Hana Doušová,
• Radim Horák,
• Zdeňka Růžičková and
• Petr Šimůnek

Beilstein J. Org. Chem. 2015, 11, 884–892, doi:10.3762/bjoc.11.99

• -catalyst L6 (Figure 2) (see method D in Supporting Information File 1, pages S25 and S26), introduced by Buchwald et al. [53] failed as well (Table 2, entries 4–6). The sterically more demanding ligand BrettPhos (L4, Figure 2), reported as a very effective ligand for N-arylations of primary amino groups

Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

• Stefanie Krysiak,
• Qiang Wei,
• Klaus Rischka,
• Andreas Hartwig,
• Rainer Haag and
• Thorsten Hugel

Beilstein J. Org. Chem. 2015, 11, 828–836, doi:10.3762/bjoc.11.92

• to an amino-functionalized site) and the catechols on the hPG is random, it will be possible to observe catechol–TiO2 interactions in some measurements and in others not. The last molecule had a catecholic functionalization for 40% of its end groups and all other end groups were amino groups, as

Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection

• Fatemeh Sheikhi Mehrabadi,
• Hanxiang Zeng,
• Mark Johnson,
• Cathleen Schlesener,
• Zhibin Guan and
• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86

• on dPG (Mn = 8.4 kDa, PDI = 1.7) were converted to amino groups according to an earlier published procedure (Scheme S1, Supporting Information File 1) [27]. The high density of amines on dPG facilitates the introduction of groups like amino acids by feasible strategies like amide coupling. Here, we

• according to a published procedure [33]. Fifty percent of all (~110) hydroxy groups on dendritic polyglycerol were functionalized with amino groups in a three-step protocol [27]. Briefly, the transformation was started with the mesylation of the hydroxy groups on dPG. In the next step, the mesylated

• in specific molar ratios. 1.2 Equivalents of BOP and DIPEA with respect to the amino groups were added to the reaction subsequently. The reaction mixture was stirred at room temperature overnight. This mixture was then transferred directly into a dialysis tube of 1000 MWCO and dialyzed in methanol

Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

• Lisa Maria Henning,
• Sumati Bhatia,
• Miriam Bertazzon,
• Michaela Marczynke,
• Oliver Seitz,
• Rudolf Volkmer,
• Rainer Haag and
• Christian Freund

Beilstein J. Org. Chem. 2015, 11, 701–706, doi:10.3762/bjoc.11.80

• according to the published procedure [19] (see Figures S2 and S3 in Supporting Information File 1 for GPC and MALDI–TOF–MS analysis of the hPG-OH core). Seventy percent of all hydroxy groups (≈120 OH groups) on hPG-OH were functionalized with amino groups in a three-step protocol as reported in the

Synthesis of a hexasaccharide partial sequence of hyaluronan for click chemistry and more

• Marina Bantzi,
• Stephan Rigol and
• Athanassios Giannis

Beilstein J. Org. Chem. 2015, 11, 604–607, doi:10.3762/bjoc.11.67

• reducing conditions (Zn, AcOH) [28] and subsequently the liberated amino groups were acetylated to furnish compound 8. Eventually, the silyl group and all benzylidene moieties were removed by treatment with Olah's reagent to give, after acetylation, derivative 9. Finally, oxidation of the terminal olefinic

3-Glucosylated 5-amino-1,2,4-oxadiazoles: synthesis and evaluation as glycogen phosphorylase inhibitors

• Marion Donnier-Maréchal,
• David Goyard,
• Vincent Folliard,
• Tibor Docsa,
• Pal Gergely,
• Jean-Pierre Praly and
• Sébastien Vidal

Beilstein J. Org. Chem. 2015, 11, 499–503, doi:10.3762/bjoc.11.56

• functionality between the 1,3,4-oxadiazole core and glucose [26] (I) or aromatic [27] (J) groups was recently investigated (Figure 1). The present study reports on the introduction of such amino groups between the oxadiazole and aromatic cores. Two synthetic strategies were used to obtain such scaffolds based

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• conventional mindset, embracing acidic, instead of alkaline acylation conditions, a potentially nimble and direct conversion of unprotected hydroxyamino acids into their corresponding side-chain esters, in a single step, can be envisaged. In a suitable acidic medium, amino groups will be prevented from

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• to conclude that the molecule of compound 11 is symmetric and bears one methine proton, two amino groups and two ethoxycarbonyl substituents. The final structure of compound 11 as 5-[2,6-diamino-3,5-bis(ethoxycarbonyl)pyridinium-1-yl]tetrazol-1-ide was confirmed by X-ray diffraction (Figure 2). The

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

• Hale Ünal,
• Naile Öztürk and
• Erem Bilensoy

Beilstein J. Org. Chem. 2015, 11, 204–212, doi:10.3762/bjoc.11.22

• based on its amino groups. Coating with CS resulted in an increment in particle size due to the adsorption of CS molecules on the nanocapsule surface [34]. This coating is believed to be of importance due to the penetration enhancing properties of chitosan through the intestinal mucosa by opening of

• to higher cellular adhesion and increasing residence time at the cell surface provided by CS molecules. This finding suggests that with chitosan-coated cationic NCs, electrostatic interactions between positively charged CS amino groups and the negatively charged cell membrane occurred. Therefore, the

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

• examined before studying the functionalization of dendronized polystyrene. Thus, di(p-methoxyphenyl)amino groups were introduced to 4 using a Buchwald–Hartwig amination [11]. The choice of a base is crucial for this transformation, and the transformation was successfully carried out using Cs2CO3 as a base

Synthetic strategies for the fluorescent labeling of epichlorohydrin-branched cyclodextrin polymers

• Milo Malanga,
• Mihály Bálint,
• István Puskás,
• Kata Tuza,
• Tamás Sohajda,
• László Jicsinszky,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3007–3018, doi:10.3762/bjoc.10.319

• fluorescent labeling was realized in three steps: 1) building in azido moieties, 2) transforming the azido groups into amino groups and 3) coupling the proper fluorescent compound to the amino groups. The other strategy started by functionalization of the monomer prior to the branching. Either the fluorescent

• the impurities level. The strategy that was built-up for achieving the labeling can introduce some undesired alteration into the polymeric structure. If the target is a strictly homogeneously fluorescent-labeled β-CD polymer, then the presence of unreacted amino groups, owing to an incomplete

• fluorescent labeling, could be an undesired modification of the starting material that can affect some properties such as the water solubility and/or ionizability. Furthermore, the quantification of these (eventual) residual amino groups would be troublesome. The strategy that was applied to overcome the

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• modulation of its amino groups at 3 and 8 positions of the phenanthridine ring [52][53]. Systematic changing of the ethidium bromide exocyclic amines into guanidine, pyrrole, urea, and various substituted ureas revealed importance of electron-donor properties of substituents at the 3- and 8-position of the

• phenanthridinium relative to the unmodified primary amino groups. Namely, derivatives of EB having substituents with weaker electron-donor properties exhibited a stronger fluorescence emission than EB, while a stronger electron-donating substituent exhibited a much lower fluorescence emission. Such behaviour could

• quenching [54][55]. Taking into account the research results of several other groups, a general rule could be drawn that phenanthridines with no amino groups yield strong fluorescence in water but emission is totally quenched by DNA binding; one amino group at (usually) position 8 results in only a small

A novel 4-aminoantipyrine-Pd(II) complex catalyzes Suzuki–Miyaura cross-coupling reactions of aryl halides

• Claudia A. Contreras-Celedón,
• Darío Mendoza-Rayo,
• José A. Rincón-Medina and
• Luis Chacón-García

Beilstein J. Org. Chem. 2014, 10, 2821–2826, doi:10.3762/bjoc.10.299

• tolerant for both electron-donating and electron-withdrawing substituents; our protocol successfully accommodated the free hydroxy and amino groups as substituents on the aryl iodides and bromides without additional protection procedures, and the reactions with these substrates produced the corresponding

Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

• Juliana P. L. Gonçalves,
• Afnan Q. Shaikh,
• Manuela Reitzig,
• Daria A. Kovalenko,
• Jan Michael,
• René Beutner,
• Gianaurelio Cuniberti,
• Dieter Scharnweber and
• Jörg Opitz

Beilstein J. Org. Chem. 2014, 10, 2765–2773, doi:10.3762/bjoc.10.293

• as control to verify the interaction of amino groups and the titanium based alloy. Furthermore, products 3 and 6 can be seen as ‘inversely modified’ DND with a terminal phosphate and a secondary amide 3 or with a primary amine and a secondary phosphoroamidate 6. This might help to assess the

• (1000 cm−1) in 4 and 5 and amino groups around 950 cm−1 and 1560 cm−1 in 4, 5 and 6. It is still possible to see some carboxylic groups on 4, which may result from an incomplete oxidation process. A positive signal of the integration of the phosphate group can be seen in 3 and 6, at the wavenumber of

• by hydrogen bridging and electrostatic affinity to positively charged amino groups. SEM results Figure 4 from unfunctionalized DND demonstrate a better interaction with the titanium oxide layer than carboxylated DND with O-PEA 3 and silanized DND 5. This may be explained by the presence of several

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• Würzburg, Germany 10.3762/bjoc.10.288 Abstract Nanodiamonds functionalized with different organic moieties carrying terminal amino groups have been synthesized. These include conjugates generated by Diels–Alder reactions of ortho-quinodimethanes formed in situ from pyrazine and 5,6-dihydrocyclobuta[d

• ]pyrimidine derivatives. For the quantification of primary amino groups a modified photometric assay based on the Kaiser test has been developed and validated for different types of aminated nanodiamond. The results correspond well to values obtained by thermogravimetry. The method represents an alternative

• wet-chemical quantification method in cases where other techniques like elemental analysis fail due to unfavourable combustion behaviour of the analyte or other impediments. Keywords: amino groups; carbon nanomaterials; Diels–Alder reaction; Kaiser test; nanodiamond; pyrazine; Introduction Surface

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

• Yamei Zhao,
• Wei Tian,
• Guang Yang and
• Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

• chain of two PHEMA blocks via a pseudo-one-step hydrosilylation reaction. Finally, modified β-CD monomers were bonded to the amino groups of PDMAEMA block side chain by the action of ionic bonds (P3). The P3 self-assembled into stable micelles with a core–shell structure in aqueous solution. The

• groups of HBPCSi (Supporting Information File 1, Figures S6 and S7). Next, P3 was synthesized by the quaternization reaction of the amino groups of the PDMAEMA block side chain with monoiodide-substituted β-CD (mono-6-I-β-CD) (Supporting Information File 1, Scheme S3). The corresponding reaction

• [23][24]. Thus, the positive charge of the current polymers should be ascribed to the presence of the PDMAEMA segments carrying tertiary amino groups. Therefore, when P1, P2 and P3 self-assembled into the micelles in aqueous solution, the PDMAEMA segments formed the outer shell of micelles, leading to