Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

• Silvia Bernardi,
• Paola Fezzardi,
• Gabriele Rispoli,
• Stefania E. Sestito,
• Francesco Peri,
• Francesco Sansone and
• Alessandro Casnati

Beilstein J. Org. Chem. 2014, 10, 1672–1680, doi:10.3762/bjoc.10.175

• macrocycle, we decided to exploit the easily available and highly versatile p-aminocalixarene 6 prepared according to literature procedures [25]. The coupling reaction between amino-calix[4]arene 6 and 4-pentynoic acid (7) in the presence of dicyclohexylcarbodiimide (DCC) led to compound 8 in 44% yield. Due

• macrocycle arms to the saccharide units. On the basis of the comparison between the efficiency of the conjugation steps bringing to glycoconjugates 9 and 13 (yields >80% in both cases) and contrary to the observation by Marra et al. [37], we could not collect any evidence for an autocatalytic effect in the

Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

• Simon Rondeau-Gagné,
• Jules Roméo Néabo,
• Maxime Daigle,
• Katy Cantin and
• Jean-François Morin

Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167

• -assembly of two new phenylacetylene macrocycle (PAM) organogelators were performed. Polar 2-hydroxyethoxy side chains were incorporated in the inner part of the macrocycles to modify the assembly mode in the gel state. With this modification, it was possible to increase the reactivity of the macrocycles in

• alkyne protective group, the half-macrocycle 5 was obtained by Castro–Stephens–Sonogashira coupling with previously reported 3,5-diiodooctylbenzene [39] in good yields despite of the possible polymerization side reaction (54% yield). TMS-protected alkynes were, then, installed on the half-macrocycle to

• approach was used for PAM3. Starting from previously synthesized compound 3, the half-macrocycle 9 was obtained by standard Castro–Stephens–Sonogashira coupling with dialkyne 8 in good yield (59%). It is noteworthy that compound 8 was obtained from oxidative deprotection of compound 7. After installing TMS

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• shape, involving both cyclic π-electron rich and π-electron deficient substrates [23][25]. The calculated thermodynamic binding constants are reported in Table 3. In the case of macrocycle 4d, a 1:1 binding isotherm could be efficiently employed to fit the titration data, strongly indicating that a 1:1

• the Hill equation [42] gave an average binding constant of 1600 M−1, thus confirming a higher affinity for the π-electron rich thiophene-derived spacer units. The Hill coefficient [43][44] suggests the presence of concomitant 1:1 and 1:2 C60:macrocycle complexes in solution. Even more interestingly

• concentration dissolved in solution A, so that the guest always remains at the same, constant concentration. In the case of a 1:1 binding isotherm (Figure 4, bottom), by employing a nonlinear fitting curve program, the plot of A against the macrocycle concentration x was fitted by Equation 1, thus affording the

Substitution effect and effect of axle’s flexibility at (pseudo-)rotaxanes

• Friedrich Malberg,
• Jan Gerit Brandenburg,
• Werner Reckien,
• Oldamur Hollóczki,
• Stefan Grimme and
• Barbara Kirchner

Beilstein J. Org. Chem. 2014, 10, 1299–1307, doi:10.3762/bjoc.10.131

• ][2][3]. They are mechanically interlocked molecules consisting of a macrocycle, called “wheel”, threaded on a linear chain, termed “axle”, see Figure 1 for examples. Typically, the axle has at least one recognition site – often hydrogen bond donors or acceptors [4][5] – for the wheel, because most

• macrocycle with isophtalamide units building up twofold hydrogen bonds to an acceptor axle. The Schalley group often used a similar hydrogen bond motif for the design of molecular shuttles with the Vögtle–Hunter tetralactam macrocycle next to several other combinations [13][14][15]. Fernandes et al. recently

• combination provides reliable results for both the gas phase and the solid state as shown in a number of publications by us [49][50][51] and other groups [45][52]. Structures under study The hereby considered pseuodorotaxanes (Figure 1) consist of an amide axle inside the cavity of a macrocycle, which

The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• appropriate guest molecules on this macrocycle template [7][8][9][10]. In solution, shape-persistent macrocycles aggregate into defined dimers or up to μm long fibers that can form gels (in solution) or can be casted to yield efficient sensor materials [11][12][13][14][15][16][17][18][19][20][21][22][23

• interior (1d). Results and Discussion Synthesis Template-based macrocycles The synthesis of the macrocycle 1 follows our often used strategy to dimerize appropriate rigid bisacetylenes oxidatively [48]. This coupling reaction can be performed statistically or template supported, where the latter is either

• , see Supporting Information File 1 for experimental details and reference [11] for the preparation of 2a–d). Statistical macrocycle synthesis Macrocycle 1d without intraannular substituents is obtained via statistical dimerization of the halfring 10 (Scheme 2). The half ring synthesis follows the above

Staudinger ligation towards cyclodextrin dimers in aqueous/organic media. Synthesis, conformations and guest-encapsulation ability

• Malamatenia D. Manouilidou,
• Yannis G. Lazarou,
• Irene M. Mavridis and
• Konstantina Yannakopoulou

Beilstein J. Org. Chem. 2014, 10, 774–783, doi:10.3762/bjoc.10.73

• , where the azido group is connected to the β-CD moiety via the flexible aminopropyl spacer, failed with mono(6-azido-6-deoxy)-β-CD. Therefore, if steric problems are circumvented using a suitable spacer between the CD macrocycle and the azido group, the process becomes very attractive: The reaction

• preference for the self-inclusion configurations. The method can be clearly utilized for dimer formation using other cyclodextrin azides, provided that there is a long enough spacer connecting the azido group with the CD macrocycle. 1H NMR chemical shift change (Δδ) of CD cavity Η3 signal of compounds

From porphyrin benzylphosphoramidate conjugates to the catalytic hydrogenation of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin

• Marcos C. de Souza,
• Leandro F. Pedrosa,
• Géssica S. Cazagrande,
• Vitor F. Ferreira,
• Maria G. P. M. S. Neves and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2014, 10, 628–633, doi:10.3762/bjoc.10.54

• substitution was promoted by microwave irradiation in N-methyl-2-pyrrolidinone. Attempts to remove the benzyl groups of the phosphoramidate moiety by hydrogenolysis with 10% Pd/C led to the cleavage of the P–N bond and the reduction of the macrocycle to hydroporphyrin-type derivatives. The extent of the effect

• reduction of the macrocycle, thereby affording chlorin and other derivatives (Scheme 1). Considering the importance of TPPF20 as a template for further functionalizations [7] and the better suitability of chlorins for PDT compared to porphyrins due to their enhanced red-shifted Q bands [2], we decided to

• analysis (UV–vis, MS, 31P NMR and 1H NMR) of the crude mixture allowed to consider the loss of the dibenzylphosphoryl group [–P(O)(OBn)2] and the reduction of the macrocycle core. This chemical transformation on the macrocycle core was easily detected from the electronic spectrum of the crude mixtures

New sesquiterpene hydroquinones from the Caribbean sponge Aka coralliphagum

• Qun Göthel and
• Matthias Köck

Beilstein J. Org. Chem. 2014, 10, 613–621, doi:10.3762/bjoc.10.52

• not be unambiguously assigned, the constitutional isomers with respect to the position of the oxygen bridge 4a and 4b (Figure 1) are in accordance with the NMR data. This is the first compound isolated from this sponge which contains a macrocycle. Moreover, this macrocycle could probably be formed by

• unambiguous. Due to the flexibility of the macrocycle of 4 it was not possible to analyse the conformation of the pyrane. Therefore, the configurations at the centers C-1, C-2, and C-22 could not be assigned. Further investigations are hindered by the fact that compound 4 easily degrades. The HRMS-ESI

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

• Mrinal K. Bera,
• Moisés Domínguez,
• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37

• between the two isomers. According to TLC and NMR spectroscopy, macrocycle 34 was isolated as a single compound. Due to the symmetry of 34 no couplings of the olefinic protons in its 1H NMR spectrum can be observed. Thus at this stage, we were unable to assign the configuration of the double bond. In lack

• determined. DFT calculations using the B3LYP method with the basis sets 6-31(d) or 6-31G(d,p) both gave a ΔEZ-E value of 16.4 kJ/mol. This energy difference may be attributed to the strain of the macrocycle and higher torsion angles between the central benzene unit and the pyrimidine rings for the Z-isomer

• , 168.4 (4 s, Py), 169.3 (s, CONH), 199.8 (s, C=O) ppm; ESI–TOF (m/z): [M + Na]+ calcd for C32H34N3NaO4, 552.2833; found, 552.2844. Optimized geometries of (a) E-configured and (b) Z-configured macrocycle 34 at B3LYP/6-31G(d,p) level. The numbers represent the calculated torsion angles between the

New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei

• Annamaria Sinisi,
• Barbara Calcinai,
• Carlo Cerrano,
• Henny A. Dien,
• Angela Zampella,
• Claudio D’Amore,
• Barbara Renga,
• Stefano Fiorucci and
• Orazio Taglialatela-Scafati

Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188

• aliphatic amino acids; ii) the abundance of N-methylated residues and iii) the presence of a macrocycle made up by more than ten amino acids. Only a few theonellapeptolides have been tested for immunosuppressive activity and they revealed a moderate potency [25]. In general, the potential bioactivity of

A reductive coupling strategy towards ripostatin A

• Kristin D. Schleicher and
• Timothy F. Jamison

Beilstein J. Org. Chem. 2013, 9, 1533–1550, doi:10.3762/bjoc.9.175

• Prusov extended their synthetic method to syntheses of 15-deoxyripostatin A, and later ripostatin A itself [9]. All of these approaches to the ripostatins share several key features: use of ring-closing metathesis to form the 14-membered macrocycle, preceded by one or more Stille couplings to generate

Synthesis of skeletally diverse alkaloid-like molecules: exploitation of metathesis substrates assembled from triplets of building blocks

• Sushil K. Maurya,
• Mark Dow,
• Stuart Warriner and
• Adam Nelson

Beilstein J. Org. Chem. 2013, 9, 775–785, doi:10.3762/bjoc.9.88

• cyclopentene did not participate in the metathesis reaction, and the bridged macrocycle 53 was obtained in low yield. We have previously observed the formation of macrocyclic metathesis products in similar metathesis cascade reactions [14]. The formation of the cyclopropanes 46 and 47 as byproducts in the

Synthesis of meso-substituted dihydro-1,3-oxazinoporphyrins

• Satyasheel Sharma and
• Mahendra Nath

Beilstein J. Org. Chem. 2013, 9, 496–502, doi:10.3762/bjoc.9.53

• Satyasheel Sharma Mahendra Nath Department of Chemistry, University of Delhi, Delhi 110 007, India 10.3762/bjoc.9.53 Abstract Novel dihydro-1,3-oxazinoporphyrins and naphtho[e]bis(dihydro-1,3-oxazinoporphyrin) derivatives, in which the porphyrin macrocycle is covalently linked to the dihydro-1,3

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• methylated host analogue TRIMEB, where the primary methoxy groups typically act as a “lid”, sealing that side of the macrocycle. In the DIMEB·1 complex, there is thus no distinct “boundary” separating the guest molecules within the cavity of host molecule A from those within host molecule B. The tilt angles

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Polysiloxane ionic liquids as good solvents for β-cyclodextrin-polydimethylsiloxane polyrotaxane structures

• Narcisa Marangoci,
• Rodinel Ardeleanu,
• Laura Ursu,
• Constanta Ibanescu,
• Maricel Danu,
• Mariana Pinteala and
• Bogdan C. Simionescu

Beilstein J. Org. Chem. 2012, 8, 1610–1618, doi:10.3762/bjoc.8.184

• macrocycle from slipping out [13][14][15][16][17][18][19][20][21][22]. Unfortunately, the properties and mechanisms of CD-polymer polyrotaxanes have been rarely evaluated due to a lack of good solvents. In general, the CD-polymer polyrotaxanes are soluble only in DMSO and aqueous sodium hydroxide solution

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• interactions; bulky groups (also known as stoppers) are attached at the ends of the axle to prevent dethreading of the host. In the past few years many authors have demonstrated that the encapsulation of conjugated polymers into macrocycle cavities plays an important role in the construction of diverse

• agreement with the proposed structures. The coverage of the rotaxane copolymer with the macrocycle, i.e., the average number of PS-βCD macrocycles per repeating unit [23], was determined from the NMR spectral analysis and was calculated from the ratio of the integrated area of the peak assigned to the H

• [5][29][31][34], can be assigned to the contribution from the structure of the PS-βCD macrocycle, which provides a deeper insight into the blocking effect of silylated groups on the cross-coupling reaction. In order to obtain higher-molecular-weight polyrotaxanes the optimal reaction time has to be

A macrolactonization approach to the total synthesis of the antimicrobial cyclic depsipeptide LI-F04a and diastereoisomeric analogues

• James R. Cochrane,
• Dong Hee Yoon,
• Christopher S. P. McErlean and
• Katrina A. Jolliffe

Beilstein J. Org. Chem. 2012, 8, 1344–1351, doi:10.3762/bjoc.8.154

• antifungal activity against any of the species tested. This suggests that the conformation of the cyclic peptide core is important in determining the antifungal activity of these compounds, since inversion of the stereocentre of one of the amino acids in the macrocycle is expected to result in a

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

• Workalemahu M. Berhanu,
• Mohamed A. Ibrahim,
• Girinath G. Pillai,
• Alexander A. Oliferenko,
• Levan Khelashvili,
• Farukh Jabeen,
• Bushra Mirza,
• Farzana Latif Ansari,
• Ihsan ul-Haq,
• Said A. El-Feky and
• Alan R. Katritzky

Beilstein J. Org. Chem. 2012, 8, 1146–1160, doi:10.3762/bjoc.8.128

• enantiomeric recognition [22][23]. Incorporation of amino acids in abiotic anion receptors can lead to systems that mimic the anion coordination properties of anion-binding proteins [24]. Introduction of cysteine subunits into a macrocycle facilitates receptor synthesis and allows control of the relative

• bis(S-acylcysteine) 36 forming the pyridine–cysteine-containing macrocycle 40 in 70% yield (Scheme 3, see Supporting Information File 1 for experimental details). Bioassay Screening for antibacterial activity was performed for two cyclic peptidomimetics belonging to scaffold 37, namely 37a and 37b

• -containing macrocycle 39. Structures of cyclic peptides with their MIC values. Antibacterial activity in vitro. Supporting Information Supporting Information File 314: Experimental details, characterization data of synthesized compounds and antibacterial testing protocol. Acknowledgements We thank the

Toward unidirectional switches: 2-(2-Hydroxyphenyl)pyridine and 2-(2-methoxyphenyl)pyridine derivatives as pH-triggered pivots

• Christina Tepper and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2012, 8, 977–985, doi:10.3762/bjoc.8.110

• 150° are transformed into diastereomers that are different in energy. In order to receive diastereomeric derivatives of 2-(2-hydroxyphenyl)-3-methylpyridine (6) and 2-(2-methoxyphenyl)-3-methylpyridine (7) we intended to insert these units into a chiral macrocycle. Therefore, we used the macrobicyclus

Synthesis and anion recognition properties of shape-persistent binaphthyl-containing chiral macrocyclic amides

• Marco Caricato,
• Nerea Jordana Leza,
• Claudia Gargiulli,
• Giuseppe Gattuso,
• Daniele Dondi and
• Dario Pasini

Beilstein J. Org. Chem. 2012, 8, 967–976, doi:10.3762/bjoc.8.109

• ][28][29][30], we have reported on the design, synthesis and characterization of a rigid, optically active tetraamidic macrocycle with recognition capabilities towards anions (Figure 1) [31]. In fact, macrocycle (R,R)-1 could be obtained efficiently (62% in the macrocyclization step) through a

• sequential, convergent methodology. It is a 32-membered macrocycle whose cyclic backbone is composed exclusively of sp2-hybridized carbon and nitrogen atoms. An additional internal rigidification of the macrocyclic cavity is given by the presence of stable, six-membered intramolecular hydrogen bonds between

• the protected (in the form of methyl ether) phenol moieties in the 2,2' positions and the NH protons of the amide functionalities in the neighboring 3,3' positions of the binaphthyl units. Macrocycle (R,R)-1 showed modest binding affinities towards carboxylate anions, yet detectable binding of proper

Synthesis of functionalized macrocyclic derivatives of trioxabicyclo[3.3.0]nonadiene

• Sabine Leber,
• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2012, 8, 738–743, doi:10.3762/bjoc.8.83

• macrocycle does not take place. Conclusion The difficulty of reduction of the nitro compounds, in particular the 1,2,3-trisubstituted compound 11, as well as the conversion of only one of the bisdioxine units in 8 to a tetraoxaadamantane suggests that these macrocycles provide steric protection of the

• functional groups. The cavity in 8 is obviously large enough to permit the formation of one tetraoxaadamantane unit, but this will reduce the available space, with the consequence that the attack by a water molecule on the second bisdioxine unit from the concave inside of the macrocycle does not take place

• ); the NMR spectra were assigned on the basis of comparison with standard data compilations; LC–MS (CH2Cl2) m/z: 271; Anal. calcd for C12H17NO6: C, 53.13; H, 6.32; N, 5.16; found: C, 53.30; H, 6.43; N, 5.10. Bis(2-nitro-1,4-phenylene)macrocycle 8: A sample of diacid dichloride 3 (500 mg, 1.05 mmol) was

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• salts in high yields and were characterized fully by multinuclear (1H, 13C and 19F) NMR, infrared (IR) and electrospray ionization mass spectrometry (ESIMS). In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a

• -C6H2O4)4(L)2(η6-p-cymene)8](O3SCF3)8 (2c), respectively in quantitative yields [L = 1,2,4,5-tetrakis(imidazol-1-yl)benzene]. The final assemblies were characterized by multinuclear (1H, 13C and 19F) NMR, IR and ESIMS analyses. The molecular structure of tetranuclear macrocycle 2a was determined by single

• a methanolic solution of 2a at room temperature. Macrocycle 2a was crystallized in a tetragonal crystal system with I41/a space group having sixteen formula units per unit cell. A perspective view of the macrocycle 2a is depicted in Figure 3 with atom numbering, and its selected bond parameters are

A ferrocene redox-active triazolium macrocycle that binds and senses chloride

• Nicholas G. White and
• Paul D. Beer

Beilstein J. Org. Chem. 2012, 8, 246–252, doi:10.3762/bjoc.8.25

• Nicholas G. White Paul D. Beer Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, United Kingdom 10.3762/bjoc.8.25 Abstract A ferrocene bis(triazole) macrocycle was synthesised in good yield by the Eglinton coupling of an acyclic bis(alkyne) precursor and characterised in the solid

• state by X-ray crystallography. Alkylation gives the corresponding triazolium macrocycle, which binds chloride and benzoate strongly in CD3CN solution through favourable charge-assisted C–H···anion interactions, as evidenced by 1H NMR titration experiments. Preliminary electrochemical studies reveal

• that the redox-active macrocycle is capable of sensing chloride in CH3CN solution. Keywords: anion binding; C–H···anion interactions; electrochemistry; ferrocene; triazolium; Introduction The copper(I)-catalysed cycloaddition of alkynes and azides (CuAAC) [1][2] to give the 1,2,3-triazole group is