Chemoselective synthesis of diaryl disulfides via a visible light-mediated coupling of arenediazonium tetrafluoroborates and CS₂

• Jing Leng,
• Shi-Meng Wang and
• Hua-Li Qin

Beilstein J. Org. Chem. 2017, 13, 903–909, doi:10.3762/bjoc.13.91

• turns red upon exposure to sunlight due to decomposition and formation of radical species [20]. Subsequently, the photodecomposition of diazonium salts by loss of nitrogen upon exposure to light has been utilized in organic synthesis for example to remove amino groups from anilines [21] or for arylation

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• and polymerisation in the presence of amino groups makes it a cheap and suitable candidate as a molecular precursor for CD synthesis. To that end, Liu et al. demonstrated in 2011 that the microwave-assisted pyrolysis of glycerol in the presence of TTDDA afforded blue-emissive CDs with a QY of 12

• irradiation of the hydrogel yielded UV-blue emissive CDs with a range of sizes from 0.6–8.7 nm (as determined by DLS). Zeta-potential analysis yielded a value of +27 mV, indicative of an abundance of amino groups and as expected from an amino group containing chitosan starting material. In addition, the group

• wall of yeast and fungi [57]. Chitin is also the precursor of chitosan, which is formed by N-deacetylation to partially free amino groups, and is notoriously insoluble in water. Despite this fact, Shchipunov et al. demonstrated in 2015, the first hydrothermal synthesis of CDs derived from chitin in a

Sulfamide chemistry applied to the functionalization of self-assembled monolayers on gold surfaces

• Loïc Pantaine,
• Vincent Humblot,
• Vincent Coeffard and
• Anne Vallée

Beilstein J. Org. Chem. 2017, 13, 648–658, doi:10.3762/bjoc.13.64

• not complete, some amino groups still remain at the top of the layer and it contributes to the lower contact angles values observed. (2) The sulfamide moieties in the aromatic skeletons which are more hydrophilic than pure aromatic skeletons contribute to the decrease of the contact angle values

• area of protonated and not protonated amino groups on the N1s signal. The conversion rate obtained by this way is very similar to the one obtained from the S2p signal, 32 and 48% for the SAM a and SAM b, respectively. All characteristic ratios of the SAMs a and b obtained by XPS have been compared with

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• [8]. However, we did not observe complexation of pincer ligands 5c–e with inorganic or organic anions by NMR titration. The attempt to increase the anion affinity for the ligands by exhaustive alkylation of amino groups with trimethyloxonium tetrafluorborate led exclusively to methylation of hydroxy

Synthesis of multi-lactose-appended β-cyclodextrin and its cholesterol-lowering effects in Niemann–Pick type C disease-like HepG2 cells

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

Beilstein J. Org. Chem. 2017, 13, 10–18, doi:10.3762/bjoc.13.2

• Boehringer Mannheim K.K. (Tokyo, Japan), respectively. Synthesis of multi-Lac-β-CD (DSL5.6) per-6-Amino-β-CD (4) was synthesized as reported previously [17]. Lactose residues were introduced in the primary amino groups of per-6-amino-β-CD. For this experiment, 20 mL of DMSO containing per-6-amino-β-CD (4

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• (Scheme 4). A similar reaction leading to N-hydroxy-substituted 1,4,6,10-tetraazadamantanes was recently observed by us for trisoximes [57][58][59][60]. However, 1,4,6,10-tetraazaadamantanes with three N-amino groups are not accessible by the previously reported method from trisoximes [57][58][59

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• , phenols and amino groups is a classical protection method in multistep syntheses as well as a transient chemical modification to improve the bioavailaibility and bioactivity of hydrophilic drugs and natural polyols [1][2][3][4][5][6][7][8][9]. Several in vitro and in vivo studies on peracetylated

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

• paper, we describe the application of Doherty’s synthetic strategy for the synthesis of stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)” compounds bearing secondary amino groups for functionalization. The attachment of a 3,5-dichlorobenzoyl binding site is reported and non-covalent interactions as

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• reactive amino-functionalized oligomers. Further modification of the free amino groups with 1,4-difluoro-9,10-anthraquinone (DFA) yields red-colored oligomeric anthraquinone dyes. The final reaction of DFA-substituted N-VP oligomers with Jeffamine® M 600 leads to blue-colored and branched oligomers with

• bonds of 2a were subjected to further modification through a thiol–ene [40][41][42] click reaction with 2-aminoethanethiol hydrochloride yielding oligomer 4 (Scheme 2). Subsequently, the reactivity of the primary amino groups in 4 was proven by the attachment of 1,4-difluoro-9,10-anthraquinone (DFA

• reactive amino groups for further modifications. The successful reaction of 4 with DFA can be monitored by 1H NMR spectroscopy through the appearance of an aromatic NH signal at about 10 ppm and additionally on the change of the chemical shifts of the protons next to the fluoro substituents in attached DFA

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• of oligonucleotides) or an activated carboxylic ester for reactions with nucleophiles (for example, terminal amino groups of MGBs). The linkers have various lengths and chemical natures and can be coupled either directly during a solid-phase synthesis or post-synthetically to pre-synthesized or

• . The linker 4 is designed for functionalization of either commercial amino-modified oligonucleotides or amine-bearing polyamides. It contains an alkyne group for CuAAC and an activated ester for the acylation of amino groups. The linkers 5–7 of different lengths contain an azide group for CuAAC and a

• carboxyl group that can react after activation with the terminal amino groups of polyamides or of amino-modified oligonucleotides (see Supporting Information File 1 for full experimental data and physicochemical characteristics of compounds). In addition, commercially available reagents 9, with an oxygen

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• to the enantioselective addition of aromatic thiols to 2-phthalimidoacrylates 29 in high yield and good enantioselectivity (Scheme 7) [24]. A variety of electron rich, neutral, and poor thiols coupled efficiently. Impressively, the aromatic thiol 28 could be substituted with hydroxy and amino groups

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

• ), their unique architecture is characterized by an ester-linked bromopyrrole carboxylic acid and a tetrahydropyrimidine ring in which one of the amino groups is attached to a quaternary carbon center. Due to their intriguing structures in combination with the promising biological properties this class of

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

• M. Fernanda N. N. Carvalho,
• M. João Ferreira,
• Ana S. O. Knittel,
• Maria da Conceição Oliveira,
• João Costa Pessoa,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2016, 12, 732–744, doi:10.3762/bjoc.12.73

• acid-catalyzed imine formation from amino groups and carbonyl compounds as well as imine hydrolysis can easily occur [25]. The key step in the reaction sequence leading to compound 2, would then be the loss of CO2 by a variant of the Strecker degradation. This step is taken “as granted” and is not

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