Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

• Arne Klinkebiel,
• Ole Beyer,
• Barbara Malawko and
• Ulrich Lüning

Beilstein J. Org. Chem. 2016, 12, 2267–2273, doi:10.3762/bjoc.12.219

• substituents in the extended triazine linkers 2: nitro, methoxy, amino and hydroxy groups. An amino group can be obtained from a nitro group by reduction, and a hydroxy group by cleavage of a methoxy group. Therefore, it was sufficient to synthesize the nitro and methoxy-substituted acid chlorides 5 for the

DNA functionalization by dynamic chemistry

• Zeynep Kanlidere,
• Oleg Jochim,
• Marta Cal and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2016, 12, 2136–2144, doi:10.3762/bjoc.12.203

• oligonucleotides. The amino group containing phosphoramidite was used together with complementary single-strand DNA templates that influenced the Watson–Crick base-pairing equilibrium in the mixture with a set of aldehyde modified nucleobases. A significant fraction of all possible base-pair mismatches was

Economical and scalable synthesis of 6-amino-2-cyanobenzothiazole

• Jacob R. Hauser,
• Hester A. Beard,
• Mary E. Bayana,
• Katherine E. Jolley,
• Stuart L. Warriner and
• Robin S. Bon

Beilstein J. Org. Chem. 2016, 12, 2019–2025, doi:10.3762/bjoc.12.189

• nanostructures in cellulo [12][13]. The precursor of D-aminoluciferin, 6-amino-2-cyanobenzothiazole (ACBT, 8), is an attractive building block for BLI probes and for handles for CBT ligations, because of the ease of derivatisation of its amino group. Like other functionalised CBTs, ACBT is available from

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

• ) [36]. The introduction of the nitroso group through the transformation of pendant functional groups includes the oxidation of primary amines [37][38][39][40][41] (Scheme 4) and hydroxamic acids [42][43][44] (Scheme 5) and the reduction of nitro compounds [45][46][47]. As oxidants for the amino group

Three-component synthesis of highly functionalized aziridines containing a peptide side chain and their one-step transformation into β-functionalized α-ketoamides

• Lena Huck,
• Juan F. González,
• Elena de la Cuesta and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2016, 12, 1772–1777, doi:10.3762/bjoc.12.166

• ether function existent in aziridine derivatives 2 because of the presence of the 2-methoxy substituent would furnish oxonium species 7 via a Neber reaction. Its O-demethylation by the trifluoroacetate anion would yield compound 8, whose amino group would finally be trifluoroacetylated by the methyl

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

• Tai Nguyen Van,
• Audrey Hospital,
• Corinne Lionne,
• Lars P. Jordheim,
• Charles Dumontet,
• Christian Périgaud,
• Laurent Chaloin and
• Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

• 3i, respectively. Indeed, these two derivatives may be able to form an H-bond between the exocyclic amino group and the nitrogen atom in position 3 of the triazole ring, in particular for compound 3h, where the amino group is in the ortho position (Figure 3 and Supporting Information File 2). Thus

• behaves as several conformers in solution (Figure 4). Indeed, the NOESY experiment shows correlations between the two protons in the ortho position (Ho and Ho’) of the phenyl ring and the H5 of the triazole. In this case, the position of the exocyclic amino group in meta position does not allow the

• sticks) and 1q (green sticks) in the substrate binding site of cN-II. We then compared the three analogues bearing an aminophenyl substituent on the triazole ring with all possible orientations (ortho, meta or para) for the amino group (derivatives 1h, 1i and 1j). Interestingly, all of them showed very

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

• -position of anthraquinones leads to a charge transfer of electrons from the amino group to the carbonyl functionality which results in additional π–π* absorption bands in the spectra of these compounds [45]. Conclusion The synthesis of paraffin-like oligomers 2a–c via double alkylation of N-VP with 1,8

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

• [10][11][34]. Several different bifunctional linkers were designed and synthesized (Figure 3). All of them contain, on one side, an alkyne or azide group for "click chemistry” and, on the other side, either an amino group for interaction with electrophiles (for example, activated terminal phosphates

• commercially purchased ligands. The first three linkers (1–3) are designed for functionalization of commercial phosphorylated TFOs according to established protocols [32]. They contain an amino group for coupling to an activated terminal phosphate of oligonucleotides and an alkyne group for CuAAC reactions

• alkyne can be used for labelling of MGB with a fluorophore using "click chemistry" and the amino group can be used to conjugate the probe to TFO or to another polyamide [15] and vice versa. Synthesis of modified polyamides, containing an azide or alkyne group The following polyamides (11–14, Figure 6

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• . (Scheme 25) [51]. The desired N-arylisoquinolone-1-phosphonates 119 were formed through the intramolecular addition of the amino group to the ester functionality in the Kabachnik–Fields adducts 118. The yields ranged between 64% and 74% depending on the nature of the substituents present in the aromatic

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• knotted structures, where a tail peptide is threaded through a macrolactam that is formed by the condensation of the N-terminal amino group with an asparatate or glutamate side-chain carboxylate. These are highly stable structures, and lasso peptides with a variety of biological activities have been

• domain that catalyses the hydrolysis of glutamine to glutamic acid and ammonia [95]. The McjB peptidase first removes the leader peptide to expose an N-terminal amino group, which is usually a glycine residue, although other residues have been identified at this position [97][98]. McjC then catalyses

• AYDG motif on the precursor peptide. This generates an acyl–enzyme intermediate, where the C-terminus of the peptide is bound to Ser783 as an ester. The N-terminal amino group then attacks this intermediate to generate a cyclic octapeptide. This is mechanistically similar to thioesterase-catalysed

Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

• Lucian G. Bahrin,
• Henning Hopf,
• Peter G. Jones,
• Laura G. Sarbu,
• Cornelia Babii,
• Alina C. Mihai,
• Marius Stefan and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2016, 12, 1065–1071, doi:10.3762/bjoc.12.100

• amino group bound to the 1,3-dithiolium cycle (ring D). Upon testing these flavonoids against Staphylococcus aureus and comparing the results with those obtained for 1, we concluded that the antibacterial activity for tricyclic flavonoids of type 5 decreases in the order NEt2 > pyrrolidine > NMe2

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• , heterocyclic groups and aliphatic groups. A plausible mechanism was proposed as shown in Scheme 29. The thiourea NH moieties and the tertiary amino group of the catalyst activated the carbonyl groups of isatin and the α-protons of gem-diols, respectively through hydrogen bond interactions. The α-proton of gem

• -diols was deprived by the amino group of the catalyst, and then the anion attacked isatin from the Re face, followed by release of one mol equivalent trifluoroacetate. The enol anion retrieved the proton from the catalyst to give the (S)-products. In 2013, Chimni and co-workers designed the cinchona

• amine of the catalyst and ketone substrate and protonation of the tertiary amino group. The protonated amine then served as hydrogen bond donor to activate the carbonyl group of isatin substrates, thereby facilitating the aldol addition. Interestingly, the authors obtained the R-/S-enantiomer by using

Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

• Phil M. Pithan,
• David Decker,
• Manlio Sutero Sardo,
• Giampietro Viola and
• Heiko Ihmels

Beilstein J. Org. Chem. 2016, 12, 854–862, doi:10.3762/bjoc.12.84

• ][22][23][24][25]. We refrained from using additional donor functionalities such as the amino group, because we observed in a previous work that these substituents cause significant fluorescence quenching and lead to only weakly fluorescent derivatives [14]. Herein, we report the synthesis of novel 3

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• employing radiolabelled UDP-N-acetylglucosamine. Disubstituted analogues were not active at the concentrations tested, suggesting that one free amino group is vital for activity. Hydantoin-derived compounds 79 with C12H25 and 80 with PhCH2 as residues R at the hydantoin moiety gave the best results with

• the observation that fully protected compounds were not active at all, as well as the completely deprotected analogues. Remarkably, some partially protected congeners 87–90 with the free terminal amino group were found to show good inhibition (MIC = 1–16 μg/mL) of the growth of Gram-positive bacteria

• give uridine-5'-aldehyde 99. Aldehyde 99 then supposedly undergoes an aldol addition with glycine 100 as the enol(ate) component, thus furnishing the amino acid–nucleoside hybrid 5'-C-glycyluridine (GlyU, 101). Alkylation of the 6'-amino group is then achieved by reaction with S-adenosyl methionine

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• by fluoridolysis of 1,6:3,4-dianhydro-2-azido-β-D-galactopyranose with KHF2. The amino group was introduced and masked as an azide in the synthesis. The 1-O-deacetylated 3-fluoro and 4-fluoro analogs of acetylated D-galactosamine inhibited proliferation of the human prostate cancer cell line PC-3

• in terms of product purity. Hydrogenolysis of 42 on palladium in ethanol/HCl followed by acetylation of the amino group furnished the target acetylated 3-fluoro-D-GlcNAc 5 as a chromatographically separable mixture of anomers (Table 1). Addition of HCl was found necessary to effect a clean

cis–trans-Amide isomerism of the 3,4-dehydroproline residue, the ‘unpuckered’ proline

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2016, 12, 589–593, doi:10.3762/bjoc.12.57

• acids. Though, the carboxyl function is influenced more strongly by the double bond, whereas the amino group is more affected by the structurally proximal 4-CF3-substituent. Conversely, the backbone conformational properties and the s-trans/s-cis energy differences remain nearly non-affected in both

Studies on the synthesis of peptides containing dehydrovaline and dehydroisoleucine based on copper-mediated enamide formation

• Franziska Gille and
• Andreas Kirschning

Beilstein J. Org. Chem. 2016, 12, 564–570, doi:10.3762/bjoc.12.55

• , they can also be regarded as enamines. Due to the lack of reactivity of the amino group as well as the carboxylate, dehydroamino acids have hardly employed as building blocks in peptide synthesis. Therefore, the olefinic double bond is commonly introduced after the peptide backbone is assembled and

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

• of the CD scaffold with two different linkers (both polyamines) and then on the coupling of the terminal amino group of the linkers with rhodamine B. The coupling conditions were slightly different from those reported by Harada [14]. The solvent was a mixture of pyridine and DMF, the activating

• -aminoethylamino)-β-CD was obtained by in situ conversion of the terminal amino group of the fluorophore into isothiocyanate group. To summarize, fluorescein has been connected to CDs through an ester bond by performing the reaction in water or DMF. Although the synthetic procedure is well described, the

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• of 71%. The suggested mechanism for this catalytic reaction involves a bifunctional activation. Utilizing the primary amino group, the authors proposed that the catalyst condenses to form an imine, which is in equilibrium with the corresponding enamine of isobutyraldehyde, while the two hydrogens of

• % and complete regiocontrol. The authors proposed that the primary amino group of the organocatalyst condenses with the ketone, to form the corresponding enamine, which in turn reacts with the electrophilic alkene 9. Jacobsen and co-workers have introduced a number of (thio)ureas as organocatalysts for

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

• Streptomycetes [5][6][7][8][9][10]. It consists of an N-acetylcysteine, a D-glucosamine, and a D-myo-inositol moiety (Figure 1). D-Glucosamine is α-linked to D-myo-inositol at the 1-position, and N-acetylcysteine is linked to the amino group of D-glucosamine. The conformation of MSH has been investigated by NMR

Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

• Barış Binay,
• Dilek Alagöz,
• Deniz Yildirim,
• Ayhan Çelik and
• S. Seyhan Tükel

Beilstein J. Org. Chem. 2016, 12, 271–277, doi:10.3762/bjoc.12.29

• formed between the aldehyde group of the modified Immobead 150 support and the terminal amino group of the enzyme at pH 6.0. Kim et al. [17] investigated the thermal stability of free C. boidinii FDH and immobilized FDH as cross-linked enzyme aggregates and reported that cross-linked enzyme aggregates of

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

• , IR, GPC and DSC methods. The kinetics of the deprotection step was followed by 1H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed. Keywords: amino group protection; bromo-tert-butyloxycarbonyl; deprotection; free radical

• (Scheme 4). Conclusion It can be concluded from the above described results that the bromo-tert-butyloxycarbonyl group has a certain potential for the preparation of amino group containing functional (meth)acryl polymers. Since the deprotection takes place under mild conditions in polar solvents, some

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• ) via the well-known Trp degradation pathway, the corresponding amino group is found in the ortho-position. An unusual 1,2-shift via the oxirane intermediate 77 was proposed for the formation of the starter unit 78. Using fluorine as a non-reactive anchor on the benzene ring in feeding experiments with

• different isomers of fluoroanthranilic acid, the fate of the amino and the carboxylic acid group in the biosynthesis of antimycins could be followed [85]. Incorporation of 3-fluoro (R1 = F) and 4-fluoroanthranilic acid (R2 = F) into antimycins was observed with retention of the position for the amino group

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• synthesized by a reaction of 1-(chlorocarbonyl)ferrocene with the terminal amino group of methoxypoly(ethylene glycol)amine (Mw = 5000 g/mol) in dichloromethane, using an excess of triethylamine as a base, followed by precipitation from diethyl ether. To evaluate the association constant of the Fc moiety with

A concise and efficient synthesis of benzimidazo[1,2-c]quinazolines through CuI-catalyzed intramolecular N-arylations

• Xinlong Pang,
• Chao Chen,
• Ming Li and
• Chanjuan Xi

Beilstein J. Org. Chem. 2015, 11, 2365–2369, doi:10.3762/bjoc.11.258

• even at elevated temperatures (Table 1, entries 5–9). Other copper salts such as Cu(OTf)2, CuBr or CuCl were also able to catalyze the reaction, but they were not as efficient as CuI as the catalyst (Table 1, entries 5–9). It is worth mentioning that the imino group (sp2) other than the amino group