Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• the macrocycle would be desirable. One possibility is the utilization of monofunctionalized CBs with outer cavity-attached fluorescent dyes [22][24]. This principally allows for the modular construction of various Förster resonance energy transfer (FRET) pairs as demonstrated with a Cy3-attached CB7

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• Sarah J. Vella Stephen J. Loeb Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada 10.3762/bjoc.14.165 Abstract A two-station [2]catenane containing a large macrocycle with two different recognition sites, one bis(pyridinium)ethane and one

• benzylanilinium, as well as a smaller DB24C8 ring was synthesized and characterized. 1H NMR spectroscopy showed that the DB24C8 ring can shuttle between the two recognition sites depending on the protonation state of the larger macrocycle. When the aniline group is neutral, the DB24C8 ring resides solely at the

• -HDB24C8]7+. Conclusion A two-station circumrotational [2]catenane has been synthesized and its operation described. The system consists of a large macrocycle containing two different recognition sites, one bis(pyridinium)ethane and one benzylanilinium with a single smaller DB24C8 ring that can shuttle

Efficient catenane synthesis by cucurbit[6]uril-mediated azide–alkyne cycloaddition

• Antony Wing Hung Ng,
• Chi-Chung Yee,
• Kai Wang and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2018, 14, 1846–1853, doi:10.3762/bjoc.14.158

• macrocycles will be ensured. One example is the use of an active metal template, in which the macrocyclization is mediated by the metal ion inside the cavity of a metal-coordinating macrocycle [20]. Cucurbit[6]uril (CB[6]) has also been demonstrated to bind to ammonium-containing azides and alkynes and to

• the covalent macrocycle formation, so that the catenanes were formed exclusively with no formation of other topological isomers. This CBAAC strategy is versatile and building blocks containing various recognition units can be used, therefore offering a convenient entry point to access more complex

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• target cancerous cells, we envisaged to graft a photoreactive RuII complex on a multivalent platform decorated with multiple RGD-containing cyclopentapeptides. A calix[4]arene moiety was chosen as the multivalent platform as this rigid macrocycle displays two distinct faces that can be selectively

Synthesis of diamido-bridged bis-pillar[5]arenes and tris-pillar[5]arenes for construction of unique [1]rotaxanes and bis-[1]rotaxanes

• Ying Han,
• Li-Ming Xu,
• Cui-Yun Nie,
• Shuo Jiang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2018, 14, 1660–1667, doi:10.3762/bjoc.14.142

• have a longer chain functionalized group and a large macrocycle, which enabled them to be a good candidate as an efficient terminal stopper for the construction of rotaxanes. Therefore, the amidation reaction of pillar[5]arene mono(oxybutoxy)benzoic acid 3a with our previously reported amido

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

• Liu-Pan Yang,
• Song-Bo Lu,
• Arto Valkonen,
• Fangfang Pan,
• Kari Rissanen and
• Wei Jiang

Beilstein J. Org. Chem. 2018, 14, 1570–1577, doi:10.3762/bjoc.14.134

• changes are rare. In this article, we present a thorough study on the host–guest chemistry of a conformationally adaptive macrocycle, namely per-O-ethoxyzorb[4]arene (ZB4). Similar to per-O-ethoxyoxatub[4]arene, ZB4 is capable of accommodating a wide range of organic cations. However, ZB4 does not show

• wide range of organic cations [32]. ZB4 is also a conformationally adaptive macrocycle. We wondered whether ZB4 has a wide guest binding scope. It was reported that quaternary ammonium-based organic cations (1+–3+) can be hosted by zorb[4]arenes [37][38]. Quaternary ammonium cations 4+ and 5+ and other

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• electrophiles such as epichlorohydrin [6], organic carbonates [7][8][9] or bis-isocyanates [10], in variable ratios depending on the required degree of reticulation. The process, of course, exploits the nucleophilic reactivity of the hydroxy groups of the macrocycle oligosaccharide unit. In general, CyNSs

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• methyl group, which is perpendicular to the mean plane of the sterol’s ring system, and the inner H5 hydrogens of the 3rd and 4th glucopyranose of host A macrocycle. The C18 methyl group of the guest, which has the same orientation with that of C19, is located at the interface of the β-CD dimer and does

• not interact with the host molecules. The C21 cholesterol methyl group being perpendicular to the C18 and C19 methyl groups is located in the host B macrocycle cavity and is in close contact with the inner H3 atom of its 6th glucopyranose unit (H36C–C36B). The aliphatic tail of the cholesterol

Synthesis of a sucrose-based macrocycle with unsymmetrical monosaccharides "arms"

• Karolina Tiara,
• Mykhaylo A. Potopnyk and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2018, 14, 634–641, doi:10.3762/bjoc.14.50

• positions in 6,6’-diamino-1’,2,3,3’,4,4’-hexa-O-benzyl-6,6’-dideoxysucrose (2) were elongated with the same polyhydroxylated unit 1 providing diamide 3, which subsequently underwent cyclization under the chosen ring-closing metathesis (RCM) conditions [29][30] to give the 21-membered macrocycle 4 (Scheme 1

• to 16 (in 60% yield). Both nitro compounds 14 and 16 were reduced to the corresponding amines 17 and 18 with sodium dithionite (Scheme 3). The synthesis of the macrocycle with different arms at both terminal positions was initiated from 6’-O-tert-butyldiphenylsilyl-1’,2,3,3’,4,4’-hexa-O-benzylsucrose

• –Grubbs catalyst (II gen.) afforded the target macrocycle 25 in 26% yield (Scheme 4). The E-configuration of the newly created C=C-bond in the final product was proven by 1H NMR analysis (J15-15’ = 15.9 Hz). Conclusion In summary, we proposed an efficient method of the synthesis of a 31-membered

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• the meso-linked phenyl substituents on the porphyrin core was located above the corrole macrocycle and was affected by the ring current. These phenyl protons appear strongly shifted toward higher field. The positions of the protons were assigned by comparing previously reported β–meso-substituted

• . Inner N–H protons of the corrole macrocycle gave a very broad signal and could not be determined due to its high unsymmetrical property and an excess amount of tautomeric structures. The N–H protons of the porphyrin macrocycle resonated at −2.46 ppm (Supporting Information File 1, Figure S1). The

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• derivatives, obtained by anchoring suitable polyammonium or imidazolium pendant groups onto the main macrocycle scaffold [23][24][25][26][27][28]. The latter example is interesting, because of the well-known ability of these macrocycles to form inclusion complexes with diverse organic guest molecules [29][30

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• linked to the methylene bridges at the 2, 8, 14 and 20 positions of the macrocycle scaffold, specifically in order to address the interaction with the host cavity and, possibly, the pendant proline moieties. The structure of the final product was confirmed by NMR (see Supporting Information File 1 for

• , respectively. These results appear quite interesting when compared with the value of the molar optical rotation of N-benzyl-L-proline, which can be deduced from literature data [56], namely −19.9 deg dm−1 M−1. If the optical activity of the macrocycle would merely depend on the presence of the amino acid

• macrocycle structure. However, the fact that Θ2, Θ3 and Θ4 values are similar indicates that extensive deprotonation of the macrocycle has a minor outcome; therefore, a significant contribution from electronic effects may be ruled out. On the other hand, large conformational rearrangements deriving from

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• organic solvents is extremely high. Therefore, TFEO-Pcs can be easily purified by silica gel column chromatography. In addition, when a phthalocyanine is substituted with an electron-donating group, such as an alkoxy group, the electron density in the phthalocyanine macrocycle increases, making it easily

• oxidized and becoming unstable. On the other hand, TFEO-Pcs are compounds that are stable and easy to handle because the electron density in the macrocycle does not increase due to the strong electron-withdrawing action of the fluorine atoms. By utilizing the robustness and high solubility of TFEO-Pcs, it

• the oxygen atom directly connected to the phthalocyanine macrocycle. The phenomenon of solvatochromism [45][46] is defined by the polarity of the solvent, and the Q band is shifted to a shorter wavelength region in a highly polar solvent. In addition to the Q band, in solvatochromism, a small

An efficient synthesis of a C₁₂-higher sugar aminoalditol

• Łukasz Szyszka,
• Anna Osuch-Kwiatkowska,
• Mykhaylo A. Potopnyk and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2017, 13, 2146–2152, doi:10.3762/bjoc.13.213

• a C12-higher sugar 1 and its application in the preparation of a polyhydroxylated macrocycle. Examples of highly functionalized sucrose derivatives from our laboratory. Preparation of C12-aminoalditol 10. Preparation of a sucrose molecule with a higher aminoalditol pendant. Supporting Information

Main group mechanochemistry

• Agota A. Gečiauskaitė and
• Felipe García

Beilstein J. Org. Chem. 2017, 13, 2068–2077, doi:10.3762/bjoc.13.204

• macrocycle [{P(μ-NiPr)2}2(μ-NiPr)]2 19 readily isomerises into the adamantoid framework, P4(NiPr)6 20, upon heating [102]. The non-viability of the tert-butyl (t-Bu) substituted adamantoid framework [103] has been rationalised on steric grounds, due to its highly sterically-encumbered nature [103][104][105

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

• Leonid S. Kikot',
• Catherine Yu. Kulygina,
• Alexander Yu. Lyapunov,
• Svetlana V. Shishkina,
• Roman I. Zubatyuk,
• Tatiana Yu. Bogaschenko and
• Tatiana I. Kirichenko

Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203

• constants of the complexes are presented in Figure 5 and Table 2. On the average, the stability of clip complexes with paraquat (7) is increased by ≈0.6 kcal/mol with increasing of the polyether macrocycle size by one oxyethylene fragment reaching a maximum for the clip 4 (Table 3). In the interaction with

• complexes are also stabilized by the C–H···O interactions between the aromatic dipyridinium protons and the oxygen atoms of the polyether macrocycle or the oxygen atoms of the carbonyl groups (the H···O distances vary in the range of 2.33–2.89 Å). Additionally the host–guest structures are stabilized by

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• modification of the macrocycle ring size, torsional rigidity of the spacer, position of the attachment to both donor and acceptor, relative configuration of hydroxy groups, and the length of the linker [58][60][61][62][63][64][65][66][67][68][69][70][71][72]. Among early examples, xylylene and phthalimido

• trimethylsilyl triflate gave the desired α-linked product 24 in 66% yield [51]. Xylylene tether Generally during glycosylation, it has been found that the more rigid the spacers, and smaller macrocycle formed, the more selective the reaction [63][69]. As an example of this approach, a rigid xylylene linker

• size of the macrocycle formed during the glycosylation (Scheme 12) [80][81]. Thioglycoside donor 45 containing a 2-O-propargyl group and acceptor 46 with an azide-containing protecting group were connected using a click reaction to afford the tethered intermediate 47. Upon treatment with NIS/TfOH

p-tert-Butylthiacalix[4]arenes functionalized by N-(4’-nitrophenyl)acetamide and N,N-diethylacetamide fragments: synthesis and binding of anionic guests

• Alena A. Vavilova and
• Ivan I. Stoikov

Beilstein J. Org. Chem. 2017, 13, 1940–1949, doi:10.3762/bjoc.13.188

• of 3.55 × 103–7.94 × 105 M−1. Besides, the binding selectivity for F−, Cl−, CH3CO2−, and H2PO4− anions against other anions was in the range of 4.1–223.9. Substituting one or two fragments in the macrocycle with N,N-diethylacetamide groups significantly reduces the complexation ability of the

• receptor. In contrast to the 1,3-disubstituted macrocycle containing two N-(4’-nitrophenyl)acetamide moieties, the 1,2-disubstituted thiacalix[4]arene, which contains only one such fragment and a N,N-diethylacetamide moiety, selectively binds F− anions. Keywords: anion binding; synthesis; thiacalixarenes

• the ratio to 1:4:4 = macrocycle 1/Na2CO3/2-bromo-N-(4’-nitrophenyl)acetamide resulted in an increase of the yield of the 1,3-disubstituted thiacalix[4]arene to 60%. In addition, p-tert-butylthiacalix[4]arene 3 tetrasubstituted at the lower rim by N-(4’-nitrophenyl)acetamide fragments in cone

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• , namely Kishi’s 2nd and 3rd generation approaches, Burkart’s 3rd generation strategy as well as Altmann’s and Blanchard’s approaches, full elaboration of the upper (C12) side chain is performed only after formation of the macrocycle. Moreover, the majority of syntheses (all of Kishi’s syntheses, Burkart’s

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• ” packing of the β-CD monomers (Figure 4) as the hydrated β-CD structures reported so far [29][33][34][35], as well as several monomeric β-CD complexes [32][36][37]. The conformation of the β-CD macrocycle (Supporting Information File 1, Table S3) is similar to the monomeric β-CD structures [29], but more

• (after the appropriate transformation of coordinates due to different origin and axes; Supporting Information File 1, Figures S4 and S5) that the hydrated β-CD macrocycle does not superpose exactly in the lattice of “β-CD–D-NAcTrp”, which may render the two structures not quite isomorphous. It is worth

• the macrocycle in the solution structures is opposite to the orientation of L-NAcTrp in ther crystal. On the other hand, only the complex β-CD–L-NAcTrp crystallizes readily forming a dimeric complex (two host and two guest molecules) packed in broken channels, isomorphous to the known β-CD complexes

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• for the macrocyclization reaction. A reaction under high dilution (1 mM) with 5 mol % catalysts at 75 °C in ethyl acetate resulted in macrocycle 4a in 84% yield (Table 3). The structure of 4a was confirmed by 1H NMR based on the disappearance of the signal corresponding to the allyl group (from the

• reaction compared to when the compound was synthesized via the two-step process (Table 4). Lastly, the macrocycle 4m was acetylated in pyridine using acetyl chloride and a catalytic amount of DMAP to furnish diacetate 5. The 1H NMR analysis of 5 clearly showed presence of two singlets at δ 2.08 and 2.06

• , eco-friendly without compromise in yield and selectivity. Build-couple-pair (B/C/P) strategy for macrocycles. Different building blocks used for DOS. Cycloaddition reaction of alkyne-azide building block. Acetylation of macrocycle 4m. Optimization of the reaction conditions for the cycloaddition

Total syntheses of the archazolids: an emerging class of novel anticancer drugs

• Stephan Scheeff and
• Dirk Menche

Beilstein J. Org. Chem. 2017, 13, 1085–1098, doi:10.3762/bjoc.13.108

• -catalysis to get the final fragment 54 in 32% yield [85][86]. The envisioned Hoye relay RCM was catalyzed by Grubbs’ second generation catalyst to close the macrocycle in 27% yield. The final acid-mediated deprotection liberated finally archazolid B (2). Notably, no cyclization was observed in an analogous

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• taxadiene macrocycle [28]. Engineering one host alone can therefore sometimes be insufficient since there are specific elements of biosynthetic pathways that may have different production capacities in one organism or another. Zhou et al. [94] reported stable co-culture fermentation of specifically

Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

• Sophie Letort,
• Michaël Bosco,
• Benedetta Cornelio,
• Frédérique Brégier,
• Sébastien Daulon,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2017, 13, 417–427, doi:10.3762/bjoc.13.45

• , cyclosarin or tabun (Figure 1) [23][24][25][26][27][28][29][30]. In fact, these β-CD derivatives play a dual role in this process: the macrocycle traps the organophosphorus whilst the bound α nucleophile reacts with the toxic agent leading to a non-toxic derivative. Other scavengers bearing several α

• scavengers (with the groups covalently attached to the macrocycle) and with mixtures of heptakis(2,3,6-trimethyl)-β-cyclodextrin (TRIMEB) with 2-iodosobenzoic acid and/or imidazole, respectively. In addition, the degradation properties of the newly synthesized CD derivatives against methyl parathion and

• ) analyses of compounds 13 and 14 confirmed the presence of the two substituents bound to the macrocycle. Also the 1H and 13C NMR spectra showed chemical shifts attributable to the CH2 groups linked to the imidazole and iodobenzoate moieties, similar to those observed for the precursor of 1 [33]. The

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• ]. The use of the porphyrin zinc complex avoids the complexation of the tetrapyrrolic macrocycle with Pd(II) formed during the catalytic cycle, and in this way prevents the loss of the catalyst. In the first experiments, the reactions between 2-bromo-5,10,15,20-tetraphenylporphyrinatozinc(II) (1) and the