Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

• Krzysztof M. Zwoliński and
• Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

• techniques and apparatuses [11]. Particularly, the crown ether-capped (or ‘crown-capped’) porphyrins are synthesized conventionally under high-dilution conditions starting from two porphyrin building blocks bearing complementary functionalities, such as amine and either acyl chloride [12] or halomethyl [13

• partially overlapped with proton resonances of aliphatic bridges. Receptor 3b displays the properties of chemical shift reagents, similar to the previously reported crown ether-capped porphyrin [36] but of different origin. Since, the macrocyclic dibenzotetraaza[14]annulene core is antiaromatic, and shows

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• ligands of cobalt complexes 2 are superior to porphyrin ligands in terms of the model for the corrin framework of B12; both the imine/oxime-type and corrin ligands are monoanionic [57][58][59][60]. The imine/oxime-type cobalt complex 2 can be isolated in both the monoalkylated and dialkylated forms [59

Synthesis and characterization of π–extended “earring” subporphyrins

• Haiyan Guan,
• Mingbo Zhou,
• Bangshao Yin,
• Ling Xu and
• Jianxin Song

Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170

• antiaromatic character of the ear-containing macrocycle, which is quite similar to the analogous “earring” porphyrin [38]. Furthermore, the antiaromaticity of the ear-containing macrocycle is proved by the large positive NICS value in the hole as well as the anticlockwise ring currency (see Supporting

• Information File 1 for details). Although some characteristic peaks in the 1H NMR spectrum of the “earring” subporphyrin are quite similar to those of “earring” porphyrin, there are some differences in their structures. This is mainly due to the fact that the bowl-shaped subporphyrin core differs

• significantly from the saddle-shaped or nearly planar porphyrin core. To elucidate the differences in their structures, we endeavored to cultivate single crystals of 3 and collected the data. The diffraction data unambiguously confirmed the designated structure (Figure 2) and revealed that all peripheral C–C

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• including photocatalysis [6], bio-imaging [7][8], and solar-energy conversion [9], just to cite a few. Thompson and Forrest reported in 1998 on the first example of a phosphorescent emitter, namely 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (Pt(OEP)), used as dopant for the fabrication of

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

• Baris Temelli Hilal Kalkan Hacettepe University, Department of Chemistry, Beytepe Campus, 06800, Ankara, Turkey 10.3762/bjoc.14.13 Abstract The preparation of β-meso directly linked porphyrin–corrole hybrids was realized for the first time via an InCl3-catalyzed condensation reaction of 2-formyl

• -5,10,15,20-tetraphenylporphyrins with meso-substituted dipyrromethanes. Hybrid compounds have been characterized by 1H NMR, 13C NMR, 2D NMR, UV–vis absorption and fluorescence spectroscopy. Keywords: corrole; hybrid compounds; indium(III) chloride; porphyrin; porphyrinoids; Introduction Porphyrins and

• metalloporphyrins play an important role in chemistry, biology, medical and materials sciences because of their presence in biological compounds such as chlorophyll and heme molecules that have very important functions in the metabolism of living organisms [1][2]. In recent years, efforts in porphyrin chemistry

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

• . Keywords: aggregation; fluorine; phthalocyanine; subphthalocyanine; trifluoroethoxy; Introduction Phthalocyanines [1][2][3] are analogues of porphyrin condensed with four isoindoline units via a nitrogen atom and exhibit a deep blue color due to their wide 18π electron conjugation. Among them, the most

• based on their unique functions. Phthalocyanines are also expected to be applied as functional dyes. A series of compounds having a macrocyclic π-conjugated system including porphyrin are known as functional dyes. In particular, phthalocyanines have a wide range of functions and are expected to serve as

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• metal affinity chromatography (IMAC). Such types of solid phases were applied to enrich carbohydrate from extracts [61] or as chiral selectors immobilized on silica for chiral cation exchange chromatography [62] (Figure 4). Porphyrin tetra-functionalized with phosphonic acid groups was used as a

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

• Alexei N. Kiselev,
• Olga K. Grigorova,
• Alexei D. Averin,
• Sergei A. Syrbu,
• Oskar I. Koifman and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

• fields of modern organic chemistry due to their unique structure and electronic properties. These molecules have already proved to be powerful tools in phototherapy, radioimmunotherapy and imaging [1], for cancer treatment [2], and actually sophisticated theranostic porphyrin-based nanodevices have been

• application of such medicaments are antitumor remedies and non-invasive diagnostic imaging agents for PET, SPECT and MRI methods [5]. The combination of porphyrin and heterocyclic moieties in one molecule is perspective for the design of new compounds with potential powerful pharmaceutical properties. Up to

• the use of dioxane instead of DMF and the decrease in the reaction temperature down to 100 °C, did not notably change the yield of 3 (34%, Table 1, entry 3). The use of porphyrin in excess diminished the yield (Table 1, entry 4). The reaction of benzoxazole with a more acidic C–H bond resulted in a

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• diffuses in the cellular environment over short distances (few tens of nm) resulting in negligible systemic side effects. For PDT applications CDs have been conjugated with porphyrin [7] and protoporphyrin (5-aminolevulinic acid) [8] in order to enhance the membrane penetration of the PS (or its prodrug

• systems in combined phototherapies. This approach has recently led to self-assembled systems based on a porphyrin–β-CD conjugate and a tailored nitric oxide photoreleaser forming a strong inclusion complex with the β-CD cavity [9]. This supramolecular nanoassembly simultaneously releases cytotoxic 1O2 and

• nitric oxide under illumination with visible light, resulting in amplified cancer-cell mortality [9]. By attaching porphyrin to γ-CD and dimeric β-CD, which are both able to form inclusion complexes with cytotoxic drug molecules such as doxorubicin and paclitaxel, nanocarriers with multimodal therapeutic

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

• such synthetic methodology in porphyrin chemistry allowing the synthesis of new derivatives, containing β-arylvinyl substituents. Keywords: N-tosylhydrazones; Pd-catalyzed cross coupling; porphyrins; Introduction Porphyrin-type heterocycles are well known for their special role in several scientific

• diversity of structural features that can be induced in the porphyrin structure [14][15][16]. Alkenyl-type moieties are examples of versatile functional groups which are present in several biologically active natural porphyrin derivatives or are substituents that can be introduced into the macrocycles

• , affording in such way important intermediates for different synthetic strategies [4][17][18]. There are methods available allowing the insertion of alkenyl groups into porphyrin macrocycles (e.g., Heck reaction [4], metathesis [7][19][20][21], Wittig reaction [22][23]). However, palladium-catalyzed cross

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

• to create three intermolecular bonds. A ruthenium–porphyrin complex-catalyzed three-component reaction of α-diazophosphonates 180, nitrosoarenes 181, and alkynes 182 to give multifunctionalized aziridinylphosphonates 183 has been reported by Reddy et al. (Scheme 39) [77]. The desired

• conditions. CuI-catalyzed four-component reactions of methyleneaziridines towards alkylphosphonates. Ruthenium–porphyrin complex-catalyzed three-component synthesis of aziridinylphosphonates and its proposed mechanism. Copper(I)-catalyzed three-component reaction towards 1,2,3-triazolyl-5-phosphonates. Three

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