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

Synthesis of multivalent host and guest molecules for the construction of multithreaded diamide pseudorotaxanes

• Nora L. Löw,
• Egor V. Dzyuba,
• Boris Brusilowskij,
• Lena Kaufmann,
• Elisa Franzmann,
• Wolfgang Maison,
• Emily Brandt,
• Daniel Aicher,
• Arno Wiehe and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2012, 8, 234–245, doi:10.3762/bjoc.8.24

• Berlin, Germany 10.3762/bjoc.8.24 Abstract A series of di-, tri- and tetravalent axles and wheels for the synthesis of pseudorotaxanes bearing the tetralactam macrocycle/diamide axle binding motif was prepared. Starting from iodinated monovalent precursors, Sonogashira cross-coupling reactions were

• view of previous theoretical calculations on amide/tetralactam macrocycle complexes [111], which show that simple amide axles dethread in the gas phase because of a favourable entropy term arising from the increase in particle number upon complex dissociation. This entropic contribution overcompensates

• . Equipping our wheels with better solubilizing groups and using diketopiperazine axles should therefore help us to go beyond the limitations encountered in the present study. Hunter/Vögtle-type tetralactam macrocycle 1 bearing an iodo substituent at one of the isophthaloyl groups, and the diamide axle piece

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• -substituted phenol; however, in host–guest chemistry an asymmetric macrocycle can provide a site for enantioselective molecular recognition. In the case of p-tert-butylcalix[n]arenes the tert-butyl substituent can be removed, as mentioned previously, through a retro-Friedel–Crafts acylation, and replaced by

• inversion in CDCl3 was <38 kJ mol−1, in contrast with 66 kJ mol−1 for the calix[4]arene analogue. To freeze the oxacalix[3]arene conformer, through-the-annulus rotation must be prevented. This can be achieved by the introduction of sufficiently large groups on the lower rim of the macrocycle. Upper-rim

• (19). In 2001, Yamato reported an oxacalix[3]arene with pendant pyridines linked by amide bonds [34]. The intramolecular hydrogen bonds between neighbouring amide groups enforced a flattened-cone conformer for the macrocycle, which prevented binding to both metal cations and, to a large extent, alkyl

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

• Jens Eckelmann,
• Vittorio Saggiomo,
• Svenja Fischmann and
• Ulrich Lüning

Beilstein J. Org. Chem. 2012, 8, 11–17, doi:10.3762/bjoc.8.2

• Jens Eckelmann Vittorio Saggiomo Svenja Fischmann Ulrich Luning Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstr. 40, D-24098 Kiel, Germany 10.3762/bjoc.8.2 Abstract A bi-macrocycle with an incorporated isophthalamide substructure was synthesized by

• ; macrocycle; molecular recognition; Introduction In the last decade, isophthalamide derivatives have become attractive neutral hosts as anion receptors [1][2]. Some of these derivatives show a high selectivity for one anion over others [3]. Isophthalamide units have also been incorporated into macrocycles [4

• ][14][15]. The preorganization and the exact shape of the “lampshade” determine the selectivity and the difference in binding of various guests. Results and Discussion Synthesis Besides the desired bi-macrocycle 1, isophthalamide 2 was synthesized in order to compare the binding properties of a non

The allylic chalcogen effect in olefin metathesis

• Yuya A. Lin and
• Benjamin G. Davis

Beilstein J. Org. Chem. 2010, 6, 1219–1228, doi:10.3762/bjoc.6.140

• . Pertinent examples have also emerged during target syntheses. In the synthesis of palmerolide A analogues by Nicolaou and co-workers, compounds 8a and 9a were found to undergo smooth macrocyclization via RCM, whereas 10a, lacking the allylic hydroxy group, failed to form the desired macrocycle under the

• . Plausible explanation for chemoselective CM of diene 16 [25]. a) Efficient cross-metathesis of S-allylcysteine [17]. b) Comparison of relative reactivity between allylic heteroatom derivatives. a) Macrocycle synthesis by carbonyl-relayed RCM. b) Putative complex in carbonyl-relayed RCM [33]. a) Sulfur