Superstructures with cyclodextrins: chemistry and applications III

• Gerhard Wenz and
• Eric Monflier

Beilstein J. Org. Chem. 2016, 12, 937–938, doi:10.3762/bjoc.12.91

• role. As exemplified in the following, CD chemistry has developed into a very attractive field of research. The cell-penetrating peptide octa-arginine was conjugated to methylated β-CD. The resulting biofunctionalized host was able to transport a porphyrin sulfonate into HeLa cells used in photodynamic

Enantioselective carbenoid insertion into C(sp³)–H bonds

• J. V. Santiago and
• A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

• literature of an enantioselective insertion of an iridium carbenoid into C(sp3)–H bonds. Che and coworkers introduced the first porphyrin-based chiral iridium catalyst (−)-65 to insertion of carbenoids into C(sp3)–H bonds [52]. The reaction with 1,4-cyclohexadiene was promoted by 1 mol % of the catalyst at

• , ranging from 2.5:1 to >20:1, favoring the anti-product, in a complementary sense when compared to the results reported by Suematsu and Katsuki for iridium catalyst 61a (Table 8). Poor to excellent yields and high enantioselectivity were reported for the main product. The chiral porphyrin-based iridium

• rhodium carbenoid insertion into C(sp3)–H bond strategy [69]. The desired product was obtained in very good yield and excellent diastereo- and enantioselectivity favoring the cis isomer (Scheme 22). An interesting work was reported by Che and coworkers concerning the first rhodium porphyrin-based catalyst

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• through judicious combination of metal and ligands. In 1982, Callot and Metz reported Rh(III) porphyrins catalyzed intermolecular C–H insertion, which showed an extraordinary selectivity for 1° C–H bonds [28]. Other metal porphyrin complexes, such as Os [29], Fe, Cu, Ag [30], can also serve as catalysts

• . Rh-porphyrin complexes for catalytic intermolecular C–H insertions. Asymmetric intermolecular C(sp3)–H insertion with chiral Rh-porphyrin catalyst. Ag-Tpx-catalyzed intermolecular C–H insertion between EDA and alkanes. Ag-Tpx-catalyzed C–H insertion of methane with EDA in scCO2. Comparison of site

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• : conjugation; heterocycles; hydroquinone; linker effect; pyrrole; Introduction Quinone–pyrrole dyads have attracted interest in various applications due to the possibility of modulating the electronic interaction between the two subunits, with porphyrin–quinone dyads being well-known examples [1][2][3

Exploring architectures displaying multimeric presentations of a trihydroxypiperidine iminosugar

• Camilla Matassini,
• Stefania Mirabella,
• Andrea Goti,
• Inmaculada Robina,
• Antonio J. Moreno-Vargas and
• Francesca Cardona

Beilstein J. Org. Chem. 2015, 11, 2631–2640, doi:10.3762/bjoc.11.282

• high multivalent effects towards jack-bean α-mannosidase were reported for fullerene- [11], cyclodextrin- [12][13] and porphyrin- [14] based scaffolds decorated with 1-deoxynojirimycin (DNJ) or 1-deoxymannojirimycin as the bioactive iminosugars. Self-assembled DNJ-based glycopeptides also experienced a

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

• Nicolas Desbois,
• Sandrine Pacquelet,
• Adrien Dubois,
• Clément Michelin and
• Claude P. Gros

Beilstein J. Org. Chem. 2015, 11, 2202–2208, doi:10.3762/bjoc.11.239

• ” reaction, has been applied to the synthesis of a range of triazole-linked porphyrin/corrole to DOTA/NOTA derivatives. Microwave irradiation significantly accelerates the reaction. The synthesis of heterobimetallic complexes was easily achieved in up to 60% isolated yield. Heterobimetallic complexes were

• are promising contrast agents (CA) in MRI. Keywords: click chemistry; corrole; DOTA; microwave; NOTA; porphyrin; Introduction Magnetic resonance imaging (MRI), positron emission tomography (PET) or single photon emission computed tomography (SPECT) are actually the most commonly used imaging

• lead to a ‘marriage of convenience’ [1]. Our group previously reported the synthesis of porphyrin-DOTA-like scaffolds for multimodal imaging [2][3]. We were interested in heterobimetallic complexes incorporating both gadolinium and copper atoms. We now want to report new multimodal porphyrinoids-DOTA

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• ]. Thus, oligomers 13–15 may be considered as structural prototypes for creating new modifiable backbones. For example, porphyrin-appended U-shaped molecular tweezers 16 and 17 have been produced (Scheme 8). Compound 16 complexed C60 or C70 or their derivatives in chloroform or toluene through porphyrin

• . Under low temperature, this dynamic [2]catenane could be quantitatively generated. The intramolecular hydrogen bonds formed by the aromatic amide linkers remarkably enhanced the complexation of the porphyrin units towards the fullerene and the bipyridine ligand. Jiang further introduced amide subunits

• the formation of square-shaped 2D MOFs from a porphyrin-derived bipyridinium precursor and 2,6-dioxynaphthalene-derived ditopic precursor [85]. In this case, the 2,6-dioxynaphthalene–dipyridinium donor–acceptor complex was also stabilized by CB[8]. These results showed that generation of 2D SOFs can

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• ) and BHJSCs. So far, various electroactive units have been anchored aside the polythiophene backbone, including ferrocene [8], porphyrin [9], 2-carboxyanthraquinone [10], 1,3-dithiole-2-ylidenefluorene [11][12], dithiinoquinoxaline [13][14] and fullerene C60 [15][16]. The incorporation of acceptor

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• examples [30][31][32][33]. Other functional units such as fullerenes [34][35], cyclodextrins [36], porphyrin [37], and phthalocyanine [38][39][40] can also be introduced into the core of radial oligo-TTFs. As shown in Figure 1, TTF-annelated porphyrin 1 was synthesized by Becher and co-workers in 2001 [37

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

• fluorescence spectra of these porphyrin–xanthone dyads. Keywords: 1,3-dipolar cycloaddition; fluorescence; synthesis; triazoloporphyrin-xanthone dyads; UV–vis spectroscopy; Introduction In the past few decades, porphyrin macrocycles have emerged as a unique class of heterocyclic compounds and as most

• porphyrins can be modulated by introducing diverse functionalities on their periphery or changing the metal ions in the porphyrin core [3][4]. Due to the high thermal stability and extended π-electron system, porphyrins are very useful for the construction of molecular switches [5][6] and other organic

• photoelectric materials [7][8]. In addition, porphyrins are potentially used as photosensitizers in photodynamic therapy to treat various types of tumors [9][10]. In recent years, many hybrid molecules including porphyrin–C60 [11], porphyrin–quinones [12] and porphyrin–cyclodextrin [13] conjugates were

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• and possible hydrophobic interactions was published in 2009 by Zhang et al. [37]. They compared the monovalent interaction of a porphyrin ligand to a C60 fullerene with the bivalent interaction of two ligands to one C60 (pincer complex) in aqueous environment. Thereby the rupture length decreased from

Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks

• Mirko Lohse,
• Larissa K. S. von Krbek,
• Sebastian Radunz,
• Suresh Moorthy,
• Christoph A. Schalley and
• Stefan Hecht

Beilstein J. Org. Chem. 2015, 11, 748–762, doi:10.3762/bjoc.11.85

• Universität Berlin, Takustraße 3, 14195 Berlin, Germany. Fax: +49(0)308385-5366; Tel: +49(0)308385-2639 10.3762/bjoc.11.85 Abstract Two pairs of divalent and tetravalent porphyrin building blocks carrying the complementary supramolecular crown ether/secondary ammonium ion binding motif have been synthesized

• and their derived pseudorotaxanes have been studied by a combination of NMR spectroscopy in solution and ESI mass spectrometry in the gas phase. By simple mixing of the components the formation of discrete dimeric and trimeric (metallo)porphyrin complexes predominates, in accordance to binding

• only contributes to binding enhancement, but also helps to exert control over complex formation. For example, “molecular elevators” have been constructed by Stoddart et al. [30][31] and giant porphyrin wheels were prepared by Anderson and co-workers [32][33], both using a multivalent template strategy

Efficient deprotection of F-BODIPY derivatives: removal of BF₂ using Brønsted acids

• Mingfeng Yu,
• Joseph K.-H. Wong,
• Cyril Tang,
• Peter Turner,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 37–41, doi:10.3762/bjoc.11.6

• facilitate chromatographic purification. The parent dipyrrins are more difficult to handle but have a range of potential applications in dye and porphyrin syntheses, metal ion coordination and supramolecular chemistry [12]. Methods to enable the functionalization of dipyrrins by temporarily complexing with

A comparative study of the interactions of cationic hetarenes with quadruplex-DNA forming oligonucleotide sequences of the insulin-linked polymorphic region (ILPR)

• Darinka Dzubiel,
• Heiko Ihmels,
• Mohamed M. A. Mahmoud and
• Laura Thomas

Beilstein J. Org. Chem. 2014, 10, 2963–2974, doi:10.3762/bjoc.10.314

• fitted ascending and descending curve segments, were located at 0.48, 0.73 and 0.50 for ligands 1e, 4 and 6, respectively. Within the error margin these data correspond to a binding stoichiometry of 1:1 for complexes of 1e and 6 with DNA a2, and a stoichiometry of 3:1 for the assembly of the porphyrin

• ). Notably, the addition of the porphyrin 4 and tetraazoniahetarene 5 to ILPR-DNA a2 has a strong effect on the positive CD signal at 265 nm, leading to the development of a negative band at 260 nm at high LDR ratio (Figure 8D and 8E). In addition, induced CD (ICD) signals were observed only in the

• , the porphyrin 4 and the tetraazoniahetarene derivative 5 show similar binding affinities towards the ILPR-quadruplex thus resembling their interactions with the telomeric 22AG quadruplex [23]. This observation indicates that these ligands may bind in similar types of binding sites. It should be noted

Synthesis of an organic-soluble π-conjugated [3]rotaxane via rotation of glucopyranose units in permethylated β-cyclodextrin

• Jun Terao,
• Yohei Konoshima,
• Akitoshi Matono,
• Hiroshi Masai,
• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2014, 10, 2800–2808, doi:10.3762/bjoc.10.297

• ]rotaxane by a cross-coupling or complexation reaction of thus formed pseudo linked [3]rotaxane. Oligo(para-phenylene), oligothiophene, and porphyrin derivatives were used as π-conjugated guests with stopper groups. Keywords: cross-coupling reaction; insulated π-conjugated molecule; oligothiophene

• -phenylene) [23] and oligothiophene [24] with linked [3]rotaxane structures via the flipping phenomenon [25]. Results and Discussion Kano and co-workers reported the synthesis of a linked pseudo [3]rotaxane involving a water-soluble porphyrin unit with carboxylate groups as the guest unit by double self

• -inclusion via sequential flipping of permethylated β-cyclodextrin (PM β-CD) in water [26]. To synthesize an organic-soluble insulated π-conjugated rotaxane, we applied this technique to the synthesis of an insulated porphyrin without water-soluble functional groups. The synthetic route to the PM β-CD based

A versatile δ-aminolevulinic acid (ΑLA)-cyclodextrin bimodal conjugate-prodrug for PDT applications with the help of intracellular chemistry

• Chrysie Aggelidou,
• Theodossis A. Theodossiou,
• Antonio Ricardo Gonçalves,
• Mariza Lampropoulou and
• Konstantina Yannakopoulou

Beilstein J. Org. Chem. 2014, 10, 2414–2420, doi:10.3762/bjoc.10.251

• cancerous rather than squamous tissues [1]. δ-Aminolevulinic acid (1, ALA, Scheme 1) is a δ-amino acid precursor in the cellular biosynthesis of heme [2]. The penultimate step in this biosynthetic cycle is the iron chelation of protoporphyrin IX (PpIX), a porphyrin photosensitizer (PS) which was shown to be

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• /diglycolic anhydride using a diiminate zinc catalyst has been reported. Here, the block copolymer of poly(ester-block-carbonate) was formed through the faster reaction of CHO/anhydride coupling, and after complete conversion of the anhydride, the carbonate block was grown by CO2/CHO coupling [29]. Porphyrin

Synthesis of the first examples of iminosugar clusters based on cyclopeptoid cores

• Mathieu L. Lepage,
• Alessandra Meli,
• Anne Bodlenner,
• Céline Tarnus,
• Francesco De Riccardis,
• Irene Izzo and
• Philippe Compain

Beilstein J. Org. Chem. 2014, 10, 1406–1412, doi:10.3762/bjoc.10.144

• ], β-cyclodextrin [4][5] and porphyrin [7] cores, and with nanoparticles prepared by self-assembly of iminosugar-based glycopolypetides [6]. So far, the largest multivalent effect (up to 610-fold relative inhibition potency increase on a valency-corrected basis) has been achieved on jack bean α

• ). These results may indicate that the ligand spatial presentation in cyclopeptoid-based iminosugars 10 is not optimal to achieve a substantial multivalent effect. It has been shown recently that the use of rigid scaffolds such as porphyrin or C60 could lead to large multivalent effects (up to 200-fold on

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

• demonstrated how cyclo-p-phenylenes of suitable size are able to form very stable complexes with C60 [20]. Aida and co-workers have reported on π-electron rich, porphyrin-based cyclic structures, which are able to selectively recognize C60 [21]. In subsequent work, similar porphyrin-based systems have been

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

• Jingran Tao,
• Li-Mei Jin and
• X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

• Jingran Tao Li-Mei Jin X. Peter Zhang Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA 10.3762/bjoc.10.129 Abstract The Co(II) complex of a new D2-symmetric chiral porphyrin 3,5-DiMes-QingPhyrin, [Co(P6)], can catalyze asymmetric aziridination of alkenes with bis

• 85% ee). In addition to mild reaction conditions and generation of N2 as the only byproduct, this new metalloradical catalytic system is highlighted with a practical protocol that operates under neutral and non-oxidative conditions. Keywords: asymmetric aziridination; aziridine; chiral porphyrin

• a racemic olefin aziridination system with diphenylphosphoryl azide (DPPA) using Co(II) complexes of common porphyrin ligands as catalysts, including [Co(TPP)] (Scheme 1) [20]. Despite the first demonstration of DPPA as a new nitrene source, this Co(II)-based catalytic transformation, however

First synthesis of meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2014, 10, 808–813, doi:10.3762/bjoc.10.76

• -triphenylporphyrin. The reaction of this porphyrin with 2,5-dimethoxytetrahydrofuran, followed by the reduction of the nitro group in the presence of NiCl2/NaBH4 afforded 5-(3-amino-4-(pyrrol-1-yl)phenyl)-10,15,20-triphenylporphyrin. This triphenylporphyrin underwent a Pictet–Spengler cyclization after the reaction

• with various aromatic aldehydes followed by in situ KMnO4 oxidation to form target porphyrin analogues in good yields. The structures of all synthesized products were established on the basis of spectral data and elemental analyses. Keywords: Clauson–Kaas reaction; fluorescence; pyrrolo[1,2-a

• useful as fluorescent materials for various applications [36][37]. In recent years, numerous covalent or non-covalent supra-porphyrin arrays, based on donor–acceptor architectures have been constructed for mimicking the natural photosynthetic light harvesting systems [38][39][40]. Additionally, a variety

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

• , Portugal 10.3762/bjoc.10.54 Abstract Three new porphyrin aminoalkyl dibenzylphosphoramidates were synthesized by nucleophilic aromatic substitution of one p-fluorine atom of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF20) by primary aminoalkyl dibenzylphosphoramidates. The nucleophilic aromatic

• hydrogenation; chlorin; isobacteriochlorin; phosphoramidate; porphyrin; Introduction The use of porphyrin derivatives as photosensitizers is considered for the photodynamic therapy (PDT) of malignant tumors and the treatment of age-related macular degeneration in several countries [1][2]. It is already known

• that the efficiency of the drug greatly depends on the porphyrin amphiphilicity, which must provide good interactions with the lipid membranes and the physiological medium. Consequently, tumor localization and better selectivity can be achieved by introducing polar substituents [3]. For this reason, we

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• magnetic properties of the resulting materials. This is essential for the recording, storing and read-out processes performed in spin-based quantum information processing using nanoscale molecular architectures [3]. This has been achieved recently within a copper porphyrin–N@C60 dyad [4] and several types

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

• type reaction; synthesis; Introduction Porphyrin macrocycles are of crucial interest for their potential applications in diverse fields such as biomimetic models for photosynthesis [1][2], electronic materials [3], catalysis [4] and medicine [5][6]. In the past few decades, the synthesis of porphyrin

• [25], pyrrolidinone [26], pyrrolidine [27] and piperazine [28], to the porphyrin periphery. In addition, many porphyrin dimers and trimers have displayed significant biological efficacy [29] and some of these are used as photosensitizers in PDT applications for the treatment of various types of

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• two terminal units of porphyrin–Zn noncovalently associated to a host molecule of bis-isoquinoline 13 (Figure 14). The exposure of azo derivative 13 to light of λ = 350 ± 10 nm leads to a mixture of isomers trans/cis 22:78. Irradiation of this mixture of isomers at λ > 420 nm returns the system to an

• that distances the porphyrin units, causing a mechanical spin rotation in the bis-isoquinoline molecule similar to a pedal. This device is effective if the porphyrin–Zn and bis-isoquinoline units remain associated during the photoisomerization, i.e., the dynamics of dissociation between these units is