Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• :1 (Scheme 3, 3e). Carbonates with aryl or styryl residue can undergo the reaction smoothly (Scheme 3, 3f–k), but alkyl-substituted substrates showed low yields (Scheme 3, 3l and 3m). Moreover, secondary amines with various substituents, acyclic amines, primary amines, or even the amine moieties in

Oxidative hydrolysis of aliphatic bromoalkenes: scope study and reactivity insights

• Amol P. Jadhav and
• Claude Y. Legault

Beilstein J. Org. Chem. 2024, 20, 1286–1291, doi:10.3762/bjoc.20.111

• -halo ketone products in usually very high yields (Scheme 1a) [18][19]. However, the haloalkenes used in this previous study as α-substituted ketone precursors were limited to either styryl analogs or stilbene type haloalkenes, with the only exception of 1-bromocycloheptene as fully aliphatic

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• general, the absorption maximum of the derivatives 2b–g decreased during the photoreaction with formation of new red-shifted absorption bands. Nevertheless, the new red-shifted absorption band of the amino-substituted styryl derivative 2b in MeCN was weak and very broad, indicating only negligible

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• yields and enantioselectivity. The catalyst P13 was an even far superior catalyst than conventional BINOL and SPINOL-derived phosphoric acids. The substrate scope was investigated by varying substituents in the carbocyclic ring of indole 4. Changing the β-aryl and α-substituents in the styryl-derived

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• the corresponding pure products 2a and 2b. (±) cis-4-Phenyl-5-((E)-styryl)dihydrofuran-2(3H)-one (2a): Spectral data are consistent with those reported in the literature [41]. 1H NMR (CDCl3) δ 7.38–7.25 (m, 3H), 7.29–7.24 (m, 3H), 7.23–7.15 (m, 4H), 6.63 (d, J = 15.9 Hz, 1H), 5.65 (dd, J = 15.9 Hz

• , 6.5 Hz, 1H), 5.42–5.38 (m, 1H), 3.99–3.93 (m, 1H), 2.98 (dd, J = 17.4 Hz, 8.1 Hz, 1H), 2.91 (dd, J = 17.4 Hz, 7.4 Hz, 1H) ppm; 13C NMR (CDCl3) δ 176.3, 136.9, 135.8, 133.4, 128.9, 128.6, 128.2, 127.9, 127.8, 126.6, 123.8, 83.5, 45.6, 34.3 ppm. (±) trans-4-Phenyl-5-((E)-styryl)dihydrofuran-2(3H)-one

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• and fluoro-substituted anthranilamides and aldehydes (Figure 4). Initially, 2-amino-5-fluorobenzamide was reacted with various benzaldehydes having bromo, ethyl, methyl, styryl, and cyclohexyl groups to produce the respective cyclized products 6b–f with good to excellent yields. Similarly, biphenyl

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• chemoselective in the presence of other oxidisable moieties such as in the cases of 2i and 2j. Additionally, the stereoconfiguration of the styryl moiety was maintained as confirmed via the X-ray structure of 2j (Scheme 3). As a potential application of our previously reported synthesis of useful bicyclo[1.1.1

Synthesis of 5-arylacetylenyl-1,2,4-oxadiazoles and their transformations under superelectrophilic activation conditions

• Andrey I. Puzanov,
• Dmitry S. Ryabukhin,
• Anna S. Zalivatskaya,
• Dmitriy N. Zakusilo,
• Darya S. Mikson,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2417–2424, doi:10.3762/bjoc.17.158

• at very low temperature –70 to –60 °C, that resulted in low to moderate yields of the target acetylene derivatives. Then, electrophilic reactions of 5-acetylenyloxadiazoles 3a–d in different acids were studied. In our recent study on the electrophilic activation of 5-styryl-1,2,4-oxadiazoles 1 [24

• positive charge (0.40–0.47 e) and gives a big contribution into LUMO (16.7–30%), pointing out that this carbon is a reactive electrophilic center by charge and orbital factors. Thus, according our previous data on reactions of 5-styryl-1,2,4-oxadiazoles 1 [24] and results of the DFT calculations for

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• ) as a reagent; the thus obtained N1-styryl-substituted 4-trifluoromethylpyrimidin-2(1H)-one 5a obviously has considerable synthetic potential [49][50]. The stereochemistry of compound 5a was confirmed by a NOE NMR experiment, which demonstrated significant spatial interaction between the H6 and Hb

• protons (see Scheme 1) and therefore suggested the preferred s-trans conformation of the β-styryl substituent in a CDCl3 solution (see Supporting Information File 1). It should be noted that the attempted N1-cycloalkylation did not proceed with cyclopropyl- and cyclohexylboronic acids. Aiming at extending

• analogous enamides [57], the facile [2 + 2] photocycloaddition process likely occurred due to favorable orientation of the interacting molecules and close contacts between alkene carbon atoms in the crystal structure. Consequently, the synthesis of product 5c was performed in darkness. N1-Styryl-substituted

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• Optics and Nanophotonics, IPCMS, UMR CNRS, 7504, 67034 Strasbourg Cedex 2, France 10.3762/bjoc.16.189 Abstract Herein we report the synthesis and characterization of a new series of styryl-based push-pull dyes containing a free amino group and their Schiff base derivatives. The dyes include the

• all dyes were evaluated by thermogravimetric analysis (TGA). The TGA data showed that all dyes were thermally stable up to 250 °C. Keywords: DFT calculations; NLO; pH sensitive dyes; Schiff base; solvent effect; styryl dyes; Introduction Push-pull organic molecules are a class of organic dyes

• series of new styryl-based organic chromophores containing a free amino group and the corresponding Schiff base derivatives. The photophysical, pH sensitivity, NLO properties, and thermal stabilities of all synthesized dyes were investigated. Density Functional Theory (DFT) calculations were also

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• , fluorescent probes having an isoxazole scaffold are rare and the limited examples that are available also contain other fluorophores such as styryl, anthranyl, or pyrenyl groups in the molecules. We recently reported the synthesis of 3,5-diaryl-4-fluoroisoxazoles 3 that were found to have planar structures

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• reaction of 4-((Z)-arylidene)-2-(E)-styryl-5(4H)-oxazolones 2 with Pd(OAc)2 resulted in ortho-palladation and the formation of a dinuclear open-book complexes 3 with carboxylate bridges, where the Pd atom is C^N bonded to the oxazolone. In 3 the two exocyclic C=C bonds of the oxazolone are in a face-to

• ortho-position of the 2,4-aryl rings in the resulting bis-amino acids can be functionalized [30]. Substrates of the (Z)-4-arylidene-2((E)-styryl)-5(4H)-oxazolone type, shown in Figure 2b, are interesting starting materials for the synthesis of new 1,3-diaminotruxillic derivatives. These azlactones are

• possibilities: two different competitive C=C bonds amenable to undergo photocycloaddition and at least three different C–H bonds that can be activated by a transition metal provide the potential for a rich organic and organometallic chemistry. Moreover, both the arylidene and the styryl groups can be tuned with

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• reactions were carried out. The starting substrates were easily obtained by a Vilsmeier–Haack reaction of bicyclo[3.2.1]octadiene thiophene derivatives with dimethylformamide. From the obtained carbaldehydes, novel methyl, methoxy, and cyano-substituted styryl thienobenzobicyclo[3.2.1]octadiene derivatives

• ], previously done on similar furobicyclo[3.2.1]octadiene compounds. The previous study included the synthesis of aldehyde 03, which was via the corresponding styryl derivatives converted to the annulated products 04–07. These compounds were of particular importance due to their rigid methano-bridged junction

• purification, the aldehydes 1 and 2 were obtained in very good yields (1: 79%; 2: 68%), and subsequently used as novel starting substrates for further addition/condensation reactions. The Wittig reaction of the prepared aldehydes with the corresponding triphenylphosphonium salts provided five new styryl

Cation-induced ring-opening and oxidation reaction of photoreluctant spirooxazine–quinolizinium conjugates

• Phil M. Pithan,
• Sören Steup and
• Heiko Ihmels

Beilstein J. Org. Chem. 2020, 16, 904–916, doi:10.3762/bjoc.16.82

• a certain extent Hg2+) initially induced a ring-opening reaction that was irreversibly followed by a fast ring closure–deprotonation–oxidation sequence to give styryl-substituted naphthoxazole derivatives as the products quantitatively. For the quinolizinium-substituted spirooxazine derivative, the

• +. Keywords: oxazole; oxidation; quinolizinium; spirooxazines; styryl dyes; Introduction Spiropyrans and spirooxazines are exemplary photochromic compounds that have gained great attention in the last decades because they allow to reversibly alter and control the physical and chemical properties of

• been shown that derivatives thereof have a great potential to serve as functional units in DNA-binding ligands [54], fluorescent dyes and chemosensors [55][56][57][58][59]. Furthermore, we have already demonstrated that styryl-substituted quinolizinium derivatives exhibit ideal photophysical and DNA

Copper-catalyzed O-alkenylation of phosphonates

• Nuria Vázquez-Galiñanes,
• Mariña Andón-Rodríguez,
• Patricia Gómez-Roibás and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2020, 16, 611–615, doi:10.3762/bjoc.16.56

• readily available, dialkyl phosphonates and alkenyl(aryl)iodonium salts can be combined to form enol phosphonates in high yield and excellent selectivity. Results and Discussion We started our studies by investigating the reaction between diethyl phosphonate 1a and styryl(mesityl)iodonium triflate (2a

• copper-catalyzed reaction between H-phosphonates and vinyliodonium salts described by Eustache and co-workers [35], no formation of the P-alkenylation product was observed in any case. Different alkenyliodonium salts were also used for this transformation. Styryl(mesityl)iodonium salts bearing both

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• (I)(N^N)(DPEPhos)]PF6 was used in the chlorotrifluoromethylation of alkenes using CF3SO2Cl as the ATRA reagent. The reaction was carried out under blue light irradiation (450 nm). The methodology was applied to a broad range of substrates, including (α-)styryl derivatives, cyclic derivatives

• )(dap)2]Cl. Trifluoromethyl methoxylation of styryl derivatives using [Cu(I)(dap)2]PF6. All redox potentials are reported vs SCE. Trifluoromethylation of silyl enol ethers. Synthesis of annulated heterocycles upon oxidation with the Sauvage catalyst. Oxoazidation of styrene derivatives using [Cu(dap)2

Reversible photoswitching of the DNA-binding properties of styrylquinolizinium derivatives through photochromic [2 + 2] cycloaddition and cycloreversion

• Sarah Kölsch,
• Heiko Ihmels,
• Jochen Mattay,
• Norbert Sewald and
• Brian O. Patrick

Beilstein J. Org. Chem. 2020, 16, 111–124, doi:10.3762/bjoc.16.13

• switching of binding properties [36]. Apparently, styryl-substituted aromatic derivatives could fill this gap because the [2 + 2] photocyclization reaction of stilbenes and derivatives thereof is a well-established reversible photoreaction [37][38][39][40][41][42][43][44][45][46], and styryl dyes, in

• particular cationic ones, were shown to be efficient DNA binders [47][48][49][50][51][52][53][54][55][56][57][58]. Nevertheless, the photochromic nature of DNA-binding styryl dyes has not been applied to use them as photoswitchable DNA binders. Although, there is one reported example that demonstrates the

• deactivation of a stilbene tyrosine kinase inhibitor by a [2 + 2] photocycloaddition [59]. As the quinolizinium ion has been established as a versatile platform for the development of DNA intercalators [60], we identified styryl-substituted quinolizinium derivatives as a promising basis for the search for

Identification of optimal fluorescent probes for G-quadruplex nucleic acids through systematic exploration of mono- and distyryl dye libraries

• Xiao Xie,
• Michela Zuffo,
• Marie-Paule Teulade-Fichou and
• Anton Granzhan

Beilstein J. Org. Chem. 2019, 15, 1872–1889, doi:10.3762/bjoc.15.183

• Xiao Xie Michela Zuffo Marie-Paule Teulade-Fichou Anton Granzhan CNRS UMR9187, INSERM U1196, Institut Curie, Université Paris Sud, Université Paris Saclay, Bât. 110, Centre universitaire Paris Sud, F-91405 Orsay, France 10.3762/bjoc.15.183 Abstract A library of 52 distyryl and 9 mono-styryl

• common feature of mono- and distyryl dyes, including long-known mono-styryl dyes used as mitochondrial probes or protein stains. However, the magnitude of the G4-induced “light-up” effect varies drastically, as a function of both the molecular structure of the dyes and the nature or topology of G4

• analytes. Although our results do not allow to formulate comprehensive structure–properties relationships, we identified several structural motifs, such as indole- or pyrrole-substituted distyryl dyes, as well as simple mono-stryryl dyes such as DASPMI [2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• Supporting Information File 1), whose spectra feature characteristic constant couplings of 16.2 and 16.1 Hz. It is worth mentioning that the fluorine substitution was performed on the boron center after introduction of the styryl residues, introduction prior to the Knoevenagel reaction is known to impede it

• likely attributed to a conformationally restricted form of the dye once adsorbed which shows an absorption value closed to mono-styryl species, thus reinforcing the panchromatic absorption of this dye. As long as BOD-TTPA-alk is concerned, no significant shift of the lower energy band is observed (see

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

• -crown-5 ether; benzothiazolium crown ether-containing styryl dyes; E/Z photoisomerization; molecular solar thermal system; Introduction Molecular photoswitches permanently attract considerable interest because they hold potential for application in molecular electronic and photonic devices [1][2][3][4

• improvements and brings the scientists nearer to the identification of the “perfect” MOST system. In this connection we identified crown ether-containing styryl dyes [14][15] as promising substances due to their ability to undergo trans-to-cis photoisomerization (E/Z) with very high quantum yields. In addition

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• structure has still to be established [43]. The method could also be extended to aryl-substituted β-ketoenamide KE79 that delivered oxazole derivative OX16 in 59% yield (Scheme 23) [45]. A subsequent reduction of the carbonyl group followed by iodine-induced elimination gave the 5-styryl-substituted oxazole

• PO34. Trifluoroacetic acid-promoted conversion of LANCA-derived β-ketoenamides KE into oxazoles OX and 1,2-diketones DK. Conversion of β-ketoenamide KE79 into oxazole OX16 and transformation into 5-styryl-substituted oxazole OX17. Mechanisms of the formation of 1,2-diketones DK and of acetyl

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• styryl derivatives via CM with styrenes (Scheme 10). Under optimized reaction conditions complete conversion of reacting partners and selective formation of CM products with exclusive E-arrangement around the C=C double bonds was observed. The most suitable catalyst for CM was found to be Ru-1, in whose

• of vinylsilanes (Scheme 1). The possibility to modify vinyl and styryl derivatives of silsesquioxanes via Heck reaction has been proved. The Heck coupling of 4-bromostyrene and vinyl-POSS derivatives leads to the formation of oligomeric products containing a silsesquioxane core in the polymer

• lengths in the order of microns. Ruthenium alkylidene catalyst Ru-5 was successfully used in copolymerization of cubic silsesquioxane bearing four β-styryl and four (3-phenyloxiran-2-yl) substituents with dicyclopentadiene (DCPD) [45]. Moreover, octanorbornenyl cubic silsesquioxane was found to undergo

Mn-mediated sequential three-component domino Knoevenagel/cyclization/Michael addition/oxidative cyclization reaction towards annulated imidazo[1,2-a]pyridines

• Olga A. Storozhenko,
• Alexey A. Festa,
• Delphine R. Bella Ndoutoume,
• Alexander V. Aksenov,
• Alexey V. Varlamov and
• Leonid G. Voskressensky

Beilstein J. Org. Chem. 2018, 14, 3078–3087, doi:10.3762/bjoc.14.287

• single crystal X-ray diffraction study (Figure 2). The sequential domino reaction presumably starts with the Knoevenagel condensation of o-hydroxybenzaldehyde and N-(cyanomethyl)pyridinium salt forming styryl derivative A, which undergoes intramolecular cyclization to give 2-iminochromene salt 3

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• interactions. One of them is the styryl derivative 2, for which two polymorphs were isolated. Polymorph 2a crystallizes in the orthorhombic space group P212121, while polymorph 2b exhibits the monoclinic space group P21/c. The general structure of 2a is similar to the monoclinic C2/c modification of Ph3Bi (1a

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• -dimethylpyrazole. The reaction has been extended to 1,2,3-triazoles, benzotriazole, and pyrazole. In the latter case, the use of (styryl)(aryl)-λ3-iodanes has also proved to be possible, with the styryl moiety being selectively transferred in the first step. The following step of C–H activation then gives access