Cobalt-catalyzed nucleophilic addition of the allylic C(sp³)–H bond of simple alkenes to ketones

• Tsuyoshi Mita,
• Masashi Uchiyama,
• Kenichi Michigami and
• Yoshihiro Sato

Beilstein J. Org. Chem. 2018, 14, 2012–2017, doi:10.3762/bjoc.14.176

• selectively in over 60% yield. However, p-CF3-acetophenone (18%), acetone (14%), cyclohexanone (29%), and benzophenone (25%) were not suitable substrates for C(sp3)–H addition of 1a (figures not shown). We next examined several α-olefins 1 (3 equiv) for allylic C(sp3)–H addition to acetophenone (2a). Not only

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• our group. These were applied to the asymmetric alkylation reaction of benzophenone imine of glycine ester which has become one of the benchmark reactions for examining the performance of new phase-transfer catalysts [36]. Later in 2010, Shirakawa and Shimizu reported the synthesis of novel inherently

• asymmetric alkylation of tert-butyl glycinate benzophenone Schiff base 3 with alkyl halides 4 in a toluene–50% KOH biphasic system (Scheme 1). The corresponding α-alkyl-α-amino acid derivatives 5 were obtained in excellent yields with very low enantioselectivities (up to 9%). This is the first example of

The first Pd-catalyzed Buchwald–Hartwig aminations at C-2 or C-4 in the estrone series

• Ildikó Bacsa,
• Dávid Szemerédi,
• János Wölfling,
• Gyula Schneider,
• Lilla Fekete and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2018, 14, 998–1003, doi:10.3762/bjoc.14.85

• with benzophenone imine and subsequent hydrogenolysis. Keywords: aminoestrones; Buchwald–Hartwig amination; 13α-estrone; functionalization; microwave assisted reactions; Introduction Aminoestrones are of particular interest thanks to their diverse biological applications [1][2][3][4]. There exist

• derivative [17][18]. The C(sp2)–N cross-coupling of the triflate was achieved with benzophenone imine or benzylamine. The removal of the protecting groups resulted in 3-aminoestrone in high yields. Schön et al. developed two convenient protocols for the preparation of 3-aminoestrone using Pd(OAc)2 and Pd2

• -13α-estrone (13). The efficient C(sp2)–N coupling method elaborated above proved to be suitable for the reaction of 2-bromo-3-benzyl ether 2 and benzophenone imine as an amine precursor (Scheme 2). The deprotection was achieved by hydrogenolysis using a Pd/C catalyst. The resulting newly-synthesized 2

2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation

• Takayuki Yakura,
• Tomoya Fujiwara,
• Akihiro Yamada and
• Hisanori Nambu

Beilstein J. Org. Chem. 2018, 14, 971–978, doi:10.3762/bjoc.14.82

• to benzophenone in the presence of Oxone® (2KHSO5·KHSO4·K2SO4) as a co-oxidant at room temperature. A study on the substituent effect of the benzene ring of N-isopropyl-2-iodobenzamide on the oxidation revealed that its reactivity increased in the following order of substitution: 5-NO2 < 5-CO2Me, 3

• but was lower at 70 °C. However, the reactivity of 13 itself was not so high: the oxidation of benzhydrol (14a) with 0.3 equiv of 13, 2.5 equiv of Oxone®, and 1 equiv of Bu4NHSO4 in MeNO2/H2O (8:3) completed in 12 h at room temperature (25 °C) to produce a 98% yield of benzophenone (15a, Table 1

• benzhydrol (14a) to benzophenone (15a) catalyzed by 13 and 16–25. Oxidation of various alcohols 14b–k with 17.a Supporting Information Supporting Information File 76: Experimental details and the 1H and 13C NMR spectra of the catalysts, the substrates, and the products. Acknowledgments This research was

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

• Lin Gan,
• Xianglong Li,
• Xinyi Cai,
• Kunkun Liu,
• Wei Li and
• Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

• in a dilute solution of toluene, which could be attributed to the strong electron-withdrawing ability and excess conjugation length of fluorenone plane compared with conventional benzophenone acceptor [18]. In addition, low temperature photoluminescence (LTPL) spectra of the materials in toluene at

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• Cristina Mozo Mulero Alfonso Saez Jesus Iniesta Vicente Montiel Instituto de Electroquímica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain 10.3762/bjoc.14.40 Abstract The electrocatalytic hydrogenation of benzophenone was performed at room temperature and atmospheric pressure using

• analysis (TGA). Cathodes were prepared using Pd electrocatalytic loadings (LPd) of 0.2 and 0.02 mg cm−2. The anode consisted of hydrogen gas diffusion for the electrooxidation of hydrogen gas, and a 117 Nafion exchange membrane acted as a cationic polymer electrolyte membrane. Benzophenone solution was

• electrochemically hydrogenated in EtOH/water (90/10 v/v) plus 0.1 M H2SO4. Current densities of 10, 15 and 20 mA cm−2 were analysed for the preparative electrochemical hydrogenation of benzophenone and such results led to the highest fractional conversion (XR) of around 30% and a selectivity over 90% for the

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• diphenylsulfone or benzophenone as the acceptors. Here again, the higher twisted molecular structure of T4 was beneficial in terms of ΔEST, color purity and EL performances. Thus, the higher internal torsion of T4 furnished OLEDs with a deeper blue emission (0.154, 0.107) than devices fabricated with T3 (0.174

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• radical. Yadav and co-workers presented a metal-free radical thiol–ene approach, using benzophenone as photoredox catalyst (Scheme 13) [43]. No sacrificial oxidant is required for this reaction as benzophenone is regenerated by hydrogen atom transfer to the anti-Markovnikov radical intermediate. Aliphatic

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• -unsaturated ketones 58 (Scheme 31b). Benzophenone (BP) or anthracene-9,10-dione (AQ) were used as sensitizers under irradiation using a UV lamp at 280 nm. A radical pathway that involves CF3• was established after a negative reaction in the presence of TEMPO (TEMPO–CF3 was detected by GC–MS). An example of

Synthesis of 1,3-cis-disubstituted sterically encumbered imidazolidinone organocatalysts

• Jan Wallbaum and
• Daniel B. Werz

Beilstein J. Org. Chem. 2017, 13, 2577–2583, doi:10.3762/bjoc.13.254

• sieves. The prepared organocatalysts will be a useful contribution for the screening of a multitude of different organocatalytic transformations. Experimental General. All solvents were distilled before use unless otherwise stated. Tetrahydrofuran (THF) was distilled over sodium and benzophenone under an

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• [16]. However, the most efficient method for the synthesis of dialkyl dicyanomaleates Z-1 is the photochemical isomerization of the corresponding E-isomers. The reaction is performed in dichloromethane [17] and in the presence of benzophenone [18][19] or 1,4-dicyanobenzene [20] as photosensitizer. The

Regiodivergent condensation of 5-alkoxycarbonyl-1H-pyrrol-2,3-diones with cyclic ketazinones en route to spirocyclic scaffolds

• Alexey Yu. Dubovtsev,
• Maksim V. Dmitriev,
• Аndrey N. Maslivets and
• Michael Rubin

Beilstein J. Org. Chem. 2017, 13, 2179–2185, doi:10.3762/bjoc.13.218

• , which ultimately could help us to redirect the course of the reaction towards formation of spirolactones of type 20. To evaluate this idea, we prepared ketazinones 22 (crystal structure of ketazinone 22a was confirmed by X-ray crystallography (CCDC 1546065, Figure 3)), derived from benzophenone and

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• and purify proteins by covalent crosslinking (Figure 5). GAuNPs were synthesized by coating the metal surface via thio-chemistry with a β-D-lactose residue (recognized by a series of lectins, i.e., PNA or Ricinus communis agglutinin) and a benzophenone moiety as photoreactive group. GAuNPs were

Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

• Lukas J. Patalag and
• Daniel B. Werz

Beilstein J. Org. Chem. 2016, 12, 2739–2747, doi:10.3762/bjoc.12.270

• were distilled before use unless otherwise stated. Tetrahydrofuran (THF) and diethyl ether (Et2O) were distilled from sodium/benzophenone under an argon atmosphere. Dichloromethane (CH2Cl2) and tetrachloromethane (CCl4) were distilled from CaCl2 under an argon atmosphere. All other solvents were used

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• (m, 4H, CH), 7.30 (m, 2H, CH); EIMS m/z: 180.0579 [M]+. Benzophenone (3b) 3b from 3a: Diphenylmethanol (73.3 mg, 0.40 mmol) and RFTA (10.9 mg, 0.020 mmol) were weighed and 74.0 mg of the mixture was used for reaction. Yield: 50%. 1H NMR (300 MHz, CDCl3) 7.83–7.79 (m, 2H, CH), 7.62–7.57 (m, 2H, CH

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• solvents were used as received unless otherwise specified. Xylenes and tetrahydrofuran were distilled over sodium and benzophenone, degassed and stored under nitrogen. ADP, ADPI2, WS3, BF2(WS3), and Zn(WS3)2 were synthesized and purified according to literature procedures with minor modifications [2][5][9

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• light. The latter involves energy transfer from the photosensitizer triplet excited state to ground state molecular oxygen [5][6]. Ketoprofen (KP) is a nonsteroidal anti-inflammatory drug that contains the benzophenone (BZP, Figure 1) chromophore and displays a n,π triplet excited state [7][8][9

• determined in dichloromethane solutions using the same absorbance value (0.30) at 308 nm for each compound. A singlet oxygen quantum yield (ΦΔ) of 0.95 for perinaphthenone in dichloromethane was used as standard [22]. Chemical structure of the photosensitizing chromophores benzophenone (BZP) and 2

Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

• Phil M. Pithan,
• David Decker,
• Manlio Sutero Sardo,
• Giampietro Viola and
• Heiko Ihmels

Beilstein J. Org. Chem. 2016, 12, 854–862, doi:10.3762/bjoc.12.84

• obvious relationship. This behavior is in agreement with that of other donor–acceptor biaryl-type dyes, such as for example para-hetaryl-substituted benzophenone derivatives, whose emission properties were demonstrated to depend on a complex interplay of different solvent parameters [38]. Unfortunately

Opportunities and challenges for direct C–H functionalization of piperazines

• Zhishi Ye,
• Kristen E. Gettys and
• Mingji Dai

Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70

• on the distal nitrogen atom is likely preventing this nitrogen from attacking the electrophile and triggers an elimination process which would yield a byproduct like 29. Of particular interest, when benzophenone (Ph2CO) was used to trap the α-lithiation product of N-Boc-N’-alkylpiperazines, in

• addition to the desired products (18, 34, and 35), a significant amount of oxidized product 36 was obtained (Figure 9). The formation of this byproduct is proposed to be a sequential single-electron oxidation of the alkyllithium intermediate by benzophenone. Again, the use of a bulky alkyl group on the

Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

• David Porter,
• Belinda M.-L. Poon and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

• commercially available reagents were used without purification unless otherwise specified. Solvents for extraction and chromatography were distilled before use. Solvents for reactions were freshly distilled immediately prior to use. Tetrahydrofuran (THF) was dried over sodium wire and benzophenone

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• photogenerated copper(I) being very reactive. On irradiating aqueous reaction mixtures containing 1 mol % of 1 at 365 nm (TLC lamp) for 1 h, click reactions were shown to proceed to full conversion. Keywords: benzophenone photosensitizer; bioconjugation; click chemistry; copper; photoreduction; Introduction

• tren (tren = tris(2-aminoethyl)amine) ligand derivative [11][12] or the dmeda (dmeda = N,N’-dimethylethylenediamine) ligand [13][14] (Scheme 1). Irradiation at 365 nm of the benzophenone photosensitizer (n→π* electronic transition), introduced through the carboxylate counterion, mediated a highly

• molecules being most probably bound to the copper ions in aqueous solution, while in THF, the carboxylates interact more tightly with the copper ions. This is in agreement with the 1H NMR spectra of 1, which showed well resolved peaks for the benzophenone protons in D2O, while in THF-d8 broad resonances

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

• Chao Chen,
• Chunxin Lu,
• Qing Zheng,
• Shengliang Ni,
• Min Zhang and
• Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

• substituents (Table 2, entries 3–8) and electron-donating groups (Table 2, entries 9 and 10), and the target product could be obtained in excellent yields (90–99%). Bulkier aromatic ketone benzophenone is also tested in this reaction with 92% and 94% conversion after 3 h (Table 2, entries 11 and 12). In

A facile synthetic route to benzimidazolium salts bearing bulky aromatic N-substituents

• Gabriele Grieco,
• Olivier Blacque and
• Heinz Berke

Beilstein J. Org. Chem. 2015, 11, 1656–1666, doi:10.3762/bjoc.11.182

• standard procedures and were degassed by freeze–thaw cycles prior to use. All chemicals used were purchased from Sigma-Aldrich and used as received. The deuterated solvents were dried with sodium/benzophenone and vacuum transferred for storage in Schlenk flasks fitted with Teflon valves. 1H NMR, 13C{1H

Grubbs–Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids

• Maximilian Koy,
• Hagen J. Altmann,
• Benjamin Autenrieth,
• Wolfgang Frey and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 1632–1638, doi:10.3762/bjoc.11.178

• , Netherlands) and were dried by using an MBraun SPS-800 solvent purification system. Hexane was purchased from VWR and distilled from sodium/benzophenone under N2. Starting materials were purchased from ABCR, Aldrich, Alfa Aesar, Fluka and TCI Europe and used without further purification. KOCMe2Et was

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

• Mohamed Yacine Ameur Messaoud,
• Ghenia Bentabed-Ababsa,
• Madani Hedidi,
• Aïcha Derdour,
• Floris Chevallier,
• Yury S. Halauko,
• Oleg A. Ivashkevich,
• Vadim E. Matulis,
• Laurent Picot,
• Valérie Thiéry,
• Thierry Roisnel,
• Vincent Dorcet and
• Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

• reason [37][38][40], the corresponding N-(4-substituted phenyl)pyrroles and -indoles are rather functionalized at C3’, next to the substituent. Experimental General methods. All the reactions were performed under argon atmosphere. THF was distilled over sodium/benzophenone. ZnCl2·TMEDA was prepared as