Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• luminescent dyes. Fluorescein, eosin Y, rose bengal, tetraphenylporphine sulfonate and sulfonated aluminum phthalocyanine were employed as classical aggregation-induced quenching dyes. 2-(p-Toluidinyl)naphthalene-6-sulfonic acid and 1-anilinonaphthalene-8-sulfonic acid were selected as representatives of

• intramolecular charge-transfer dyes. Phosphated tetraphenylethylene was involved as the classical aggregation-induced emission dye. Sulfonated acedan representing one example of two-photon fluorescent probes, was also investigated. A ruthenium(II) complex with carboxylated bipyridyl ligands was included as a

• and potential applications according to the diverse photophysical responses are provided. Keywords: calixarene; host–guest complexation; luminescent dyes; macrocycles; photophysical properties; Introduction Fluorescence sensing represents a powerful detection methodology due to its low cost, ease of

N-doped carbon dots covalently functionalized with pillar[5]arenes for Fe³⁺ sensing

• Jia Gao,
• Ming-Xue Wu,
• Dihua Dai,
• Zhi Cai,
• Yue Wang,
• Wenhui Fang,
• Yan Wang and
• Ying-Wei Yang

Beilstein J. Org. Chem. 2019, 15, 1262–1267, doi:10.3762/bjoc.15.123

• ) as a rising star in fluorescent nanomaterials have attracted wide attention in terms of preparation and application [1][2][3][4]. Fluorescent C-dots possess advantages over organic dyes and traditional semiconductor quantum dots due to their high solubility, facile modification, desirable chemical

Precious metal-free molecular machines for solar thermal energy storage

• Meglena I. Kandinska,
• Snejana M. Kitova,
• Vladimira S. Videva,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• Stanislav B. Baluschev,
• Silvia E. Angelova and
• Aleksey A. Vasilev

Beilstein J. Org. Chem. 2019, 15, 1096–1106, doi:10.3762/bjoc.15.106

• Abstract Four benzothiazolium crown ether-containing styryl dyes were prepared through an optimized synthetic procedure. Two of the dyes (4b and 4d) having substituents in the 5-position of the benzothiazole ring are newly synthesized compounds. They demonstrated a higher degree of trans–cis

• photoisomerization and a longer life time of the higher energy forms in comparison with the known analogs. The chemical structures of all dyes in the series were characterized by NMR, UV–vis, IR spectroscopy and elemental analysis. The steady-state photophysical properties of the dyes were elucidated. The stability

• constants of metal complexes were determined and are in good agreement with the literature data for reference dyes. The temporal evolution of trans-to-cis isomerization was observed in a real-time regime. The dyes demonstrated a low intrinsic fluorescence of their Ba2+ complexes and high yield of E/Z

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• enables them to be effective hosts for a wide range of guest molecules including organic biscarbonyl derivatives, near-infrared dyes, acenes, precious metal halide complexes, trimethylammonium ion-pairs, and saccharides. Keywords: fluorescent dye; host–guest chemistry; hydrogen bonding; hydrophobic

• -conformational motion such as macrocycle pirouetting around the encapsulated guest [50][51]. The Smith group has found that an organic soluble version of anthracene-containing tetralactam B is able to encapsulate squaraine, thiosquaraine and croconaine dyes [33][57][58][59]. Solid-state structures of various

• squaraine complexes show the surrounding macrocycle in a flattened chair conformation. In contrast, the surrounding macrocycle adopts a boat conformation in complexes that encapsulate larger thiosquaraine and croconaine dyes (Figure 4). A recent work by Mateo-Alonso and co-workers has reported several

Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues

• Leon Buschbeck,
• Aleksandra Markovic,
• Gunther Wittstock and
• Jens Christoffers

Beilstein J. Org. Chem. 2019, 15, 981–991, doi:10.3762/bjoc.15.96

• Leon Buschbeck Aleksandra Markovic Gunther Wittstock Jens Christoffers Institut für Chemie, Universität Oldenburg, Carl von Ossietzky-Str. 9–11, D-26129 Oldenburg, Germany 10.3762/bjoc.15.96 Abstract Two bifunctional diaminoterephthalate (DAT) fluorescence dyes were prepared in a three-step

• dyes [1][2] with outstanding properties such as high quantum yields and pronounced stability against photobleaching [3][4][5]. Although being structurally relatively simple, this class of dyes is so far underrated in the literature. The chromophore, which is accessed from succinyl succinates and

• suitability for molecular surface labeling. Conclusion Two bifunctional diaminoterephthalate (DAT) fluorescence dyes have been prepared. One functional unit is α-lipoic acid (ALA) for binding the dye to gold surfaces. The other carries a trifluoromethyl group for facile detection of the surface-bound material

Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions

• Angélica de Fátima S. Barreto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88

• -MiB. Functional macrocycles have been developed with dye-modified and photoswitchable moieties by MiBs [43]. The approach employed the use of bifunctionalized near-infrared (NIR) dyes containing two carboxylic acid moieties with diisocyanide building blocks providing the formation of somewhat flexible

Catalyst-free assembly of giant tris(heteroaryl)methanes: synthesis of novel pharmacophoric triads and model sterically crowded tris(heteroaryl/aryl)methyl cation salts

• Rodrigo Abonia,
• Luisa F. Gutiérrez,
• Braulio Insuasty,
• Jairo Quiroga,
• Kenneth K. Laali,
• Chunqing Zhao,
• Gabriela L. Borosky,
• Samantha M. Horwitz and
• Scott D. Bunge

Beilstein J. Org. Chem. 2019, 15, 642–654, doi:10.3762/bjoc.15.60

• compounds [13][14][15][16]. Due to their valuable properties, they are also well exploited by the chemical industry as dyes and photochromic agents [17][18], protective groups in organic synthesis [19] and as building blocks for dendrimers [20] and nonlinear optical (NLO) properties [21] (Scheme 1

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

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

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• -triazol-1-yl)alkylidene chains as the linkers between the calixarene monomer units. Even these materials were proven effective in sequestrating organic model pollutants, such as p-nitroaniline derivatives or dyes, from aqueous solution. However, their synthesis required much longer times in comparison

• presence of unreacted alkyne groups. Sequestration abilities of the CaNS nanosponges The possible pH-responsive sequestration abilities of materials CaNS-I and CaNS-II were verified by means of sequestration tests on a set of suitable guest, namely p-nitroaniline derivatives 6–10 and dyes 11–15 (Figure 4

• comparison between guests 9 and 10, which differ only for the presence of the -NH2 tail group, is interesting. In fact, the amine group makes the guest more hydrophilic and able to be protonated; as a consequence, 10 is sequestrated much less effectively. Consistently, the behavior of dyes 11–15 confirms the

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• dyes and transition metal complexes, hypohalous acids, and persulfate anions [12][34][35][36][37][38][39][40]. An important class of catalyzed benzylic C–H to C–O transformations are those catalyzed by N-oxyl radicals. Specifically, N-oxyl radical catalysts based upon the N-hydroxyphthalimide (NHPI

Back to the future: Why we need enzymology to build a synthetic metabolism of the future

• Tobias J. Erb

Beilstein J. Org. Chem. 2019, 15, 551–557, doi:10.3762/bjoc.15.49

• the nature and reactivity of the chemical bond enabled chemists to use their knowledge to create new molecules and materials [3][4]. This development provided humankind with new chemical compounds, such as color dyes, pharmaceuticals, as well as polymers and plastics. Given its transforming nature, it

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• obtain the ABCBA pentablock copolymers. This copolymer forms nanoparticles with a central hydrophobic core capable of accommodating fluorescent dyes and conventional therapeutics and a hydrophilic biocompatible outer shell. The efficient combination of the ROMP process and click chemistry led to the

N-Arylphenothiazines as strong donors for photoredox catalysis – pushing the frontiers of nucleophilic addition of alcohols to alkenes

• Fabienne Speck,
• David Rombach and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 52–59, doi:10.3762/bjoc.15.5

• ]. The photochemical reactivity can be tuned by the absorption and excited state characteristics of the photocatalyst. In this context, organic dyes represent a perfectly suited class of photocatalysts as they can easily be modified by the introduction of functional groups that allow fine-tuning the

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• allow access to unique chemistries such as photocatalysis at different wavelength or photoconductivity for example [76]. Moreover, they can be characterized by lower costs. For examples, methylene blue or eosin-Y are examples of widespread photoredox catalytic dyes [18]. There is a wide range of

Microwave-assisted synthesis of biologically relevant steroidal 17-exo-pyrazol-5'-ones from a norpregnene precursor by a side-chain elongation/heterocyclization sequence

• Gergő Mótyán,
• László Mérai,
• Márton Attila Kiss,
• Zsuzsanna Schelz,
• Izabella Sinka,
• István Zupkó and
• Éva Frank

Beilstein J. Org. Chem. 2018, 14, 2589–2596, doi:10.3762/bjoc.14.236

• the sterane skeleton have been published, but not to C-17 [10]. Nevertheless, this heterocyclic scaffold is also an important building block in many clinically relevant drugs, agrochemicals, dyes, pigments and chelating agents [11][12][13], and therefore its introduction to C-17 of androstanes may be

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

• water) could reduce 1 to form Co(I) species upon irradiation with ultraviolet (UV) light. We also reported a visible-light-driven system with a molecular photosensitizer such as Ru(bpy)32+ [39][40][102][103], cyclometalated iridium(III) complexes [104], and organic red dyes [105][106][107]. 4-2

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

• Amrita Das,
• Mitasree Maity,
• Simon Malcherek,
• Burkhard König and
• Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

• SCE. Other photocatalysts like Ru(bpy)3Cl2, Ru(bpz)3PF6, DDQ, acridinium dyes, Eosin Y, Eosin Y disodium salt and 4-CzIPN were evaluated, but under our reaction conditions either low substrate conversion or the degradation of the photocatalyst was observed (see Supporting Information File 1, Table S1

Cobalt bis(acetylacetonate)–tert-butyl hydroperoxide–triethylsilane: a general reagent combination for the Markovnikov-selective hydrofunctionalization of alkenes by hydrogen atom transfer

• Xiaoshen Ma and
• Seth B. Herzon

Beilstein J. Org. Chem. 2018, 14, 2259–2265, doi:10.3762/bjoc.14.201

• other nitrogen-containing SOMOphiles in the HAT reaction. Employing 4-methoxyphenyldiazonium tetrafluoroborate (5a) in our HAT conditions, the alkyl aryl azo product 7a was obtained in 92% yield (Table 1, entry 10). Due to the importance of azo compounds in synthetic organic chemistry, industrial dyes

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• pharmaceutical industry. This type of chemistry has also demonstrated a high degree of sustainability, especially when organic dyes can be employed in place of often toxic and environmentally damaging transition metals. The sections are arranged according to the general class of the presented reactions and the

• mechanistic considerations are highlighted in the text when appropriate. Keywords: C–H functionalisation; heterocycles; late-stage functionalisation; medicinal chemistry; organic dyes; organic photocatalysts; peptide chemistry; photoredox catalysis; Review 1 Introduction 1.1 Main advantages of

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• are assigned to the different natures of the used dyes. In the case of EY, which is a dianion at pH 7, the interaction with the dicationic calixarenes 10a,b results in the formation of a non-charged complex, which can be referred to a non-ionic surfactant. Generally, non-ionic surfactants possess

• hydrophobic interactions with hydrophobic regions of calixarene aggregates that are typical for xanthene dyes [41]. The length of the alkyl chains in 10a,b does not affect the complex stoichiometry. Compounds 12a,b at concentrations below the CAC form dye–calixarene complexes of 2:1 stoichiometry [(X2

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

• -dipyrromethene (BODIPY) dyes as a new class of fluorophores for the design of reporter dyes for supramolecular host–guest complex formation with cucurbit[7]uril (CB7). The BODIPYs contain a protonatable aniline nitrogen in the meso-position of the BODIPY chromophore, which was functionalized with known binding

• motifs for CB7. The unprotonated dyes show low fluorescence due to photoinduced electron transfer (PET), whereas the protonated dyes are highly fluorescent. Encapsulation of the binding motif inside CB7 positions the aniline nitrogen at the carbonyl rim of CB7, which affects the pKa value, and leads to a

• fluorescent dyes directly enables (bio)sensing applications through the indicator displacement principle [16][17]. Therein, the fluorescence properties of a dye are altered when encapsulated by the host, and when a competitive binder displaces the dye from the cavity, the properties of the non-encapsulated

Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

• Siva Sankar Murthy Bandaru,
• Darinka Dzubiel,
• Heiko Ihmels,
• Mohebodin Karbasiyoun,
• Mohamed M. A. Mahmoud and
• Carola Schulzke

Beilstein J. Org. Chem. 2018, 14, 1871–1884, doi:10.3762/bjoc.14.161

• excited states are stabilized by the solvents to the same degree. As the only exception, larger red shifts of the absorption maxima of derivatives 2a–d were observed in CHCl3 and CH2Cl2, which is presumably caused by the high polarizability of these solvents, as frequently observed with cationic dyes [34

First thia-Diels–Alder reactions of thiochalcones with 1,4-quinones

• Grzegorz Mlostoń,
• Katarzyna Urbaniak,
• Paweł Urbaniak,
• Anna Marko,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2018, 14, 1834–1839, doi:10.3762/bjoc.14.156

• cycloadduct was isolated in 37% yield. Keywords: hetero-Diels–Alder reactions; quinone dyes; quinones; sulfur heterocycles; thiochalcones; Introduction Hetero-Diels–Alder reactions are considered to be a powerful methodology widely explored for the synthesis of six-membered heterocycles [1][2] with numerous

• class of 4H-thiopyran derivatives. The presence of a quinone system is an important structural aspect of this class as it is common in many naturally occurring compounds, e.g., dyes such as alizarin, carminic acid, and isoprenoid dyes, as well as drugs such as doxorubicin. In addition, the presence of

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

• , their sequestration abilities were tested in aqueous medium at different pH values, in order to assess their possible pH-tunable properties, towards a set of structurally diverse organic guests (4-nitroaniline derivatives 1–5 and dyes 6–10, Scheme 2) which were suitably selected as possible pollutant

• of CaNSs in sequestering organic species from buffered aqueous solutions were verified, using model p-nitroaniline derivatives 1–5 and dyes 6–10 as the guests. The sequestration abilities of CaNSs were estimated (see Experimental) by equilibrating a given amount of material with a fixed volume of a

• one of an additional hydrophilic primary amine group. In a second series of tests we considered a set of dyes. In particular, we selected probe molecules having diverse structural frameworks, namely an acridinium derivative (toluidine blue, 6), a diazoic (methyl orange, 7), a triarylmethane

Metal-free formal synthesis of phenoxazine

• Gabriella Kervefors,
• Antonia Becker,
• Chandan Dey and
• Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

• ][8], are present in a variety of dyes [9], and can be applied in chemosensors and dye-sensitized solar cells (Figure 1) [10][11][12]. N-Arylphenoxazines were recently employed as photoredox catalysts in metal-free polymerizations [13]. The first synthesis of phenoxazine dates back more than 100 years

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• fluorescein dyes to target mouse major satellite DNA using thermal denaturation, gel-shift electrophoresis, circular dichroism and fluorescence spectroscopy [89][90]. Some of these fluorescent probes were found to detect target sequences in mouse living cell lines and the nuclear substructures formed by