Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• ]. This reaction comprises four main steps: (i) iodide-mediated aryl transfer from boronic acid to selenium dioxide, (ii) reduction of arylseleninic acid to diaryl diselenide, (iii) oxidation of diaryl diselenide to aryl selenenyl iodide with iodine, and (iv) electrophilic substitution of aniline

• monoselenides 1 and 2, respectively. The signal at 371 ppm corresponded to compound 1, based on a previous report [47]. In turn, the other signal was assigned to the isomeric compound 2. A similar observation was made in the 77Se NMR spectra of the pure diaryl diselenide isomers obtained from the reaction of

• ). Similar to the 77Se NMR signals of isomeric diaryl diselenides 1 and 2, the symmetrical diaryl diselenide 12, having an amino group para to the selenium center in both aryl units, showed a downfield shift compared to isomer 11. The mass spectrum of oxamide 13 revealed peaks for the sodium complexes [M

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• attacks the Cu(III) intermediate 87, formed via the reaction between diaryl diselenide 84 and the bimetallic complex [L2Cu]2I2. Next, the produced intermediate 88 undergoes a reductive elimination to achieve intermediate 89 with regeneration of the Cu complex [L2Cu]2I2. Then, nucleophilic attack of the

• aryl selenide anion to the antimony atom takes place to give 5-selanyltriazole 85 and Ph2Sb–SeAr. Ph2Sb–SeAr is hydrolyzed in aqueous medium to give selenol 90 and Ph2SbOH. Selenol 90 is oxidized in air and transformed into diselenide 84. Therefore, only 0.5 equiv of diaryl diselenide were necessary

Synthesis of benzo[d]imidazo[2,1-b]benzoselenoazoles: Cs₂CO₃-mediated cyclization of 1-(2-bromoaryl)benzimidazoles with selenium

• Mio Matsumura,
• Yuki Kitamura,
• Arisa Yamauchi,
• Yoshitaka Kanazawa,
• Yuki Murata,
• Tadashi Hyodo,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2019, 15, 2029–2035, doi:10.3762/bjoc.15.199

• probably deprotonation of the heterocyclic rings with a base. Moreover, nucleophilic aromatic substitution (SNAr) reactions between an aryl halide and a selenium reagent such as aryl selenide anion or diaryl diselenide for C(Ar)–Se bond formation using a base have been reported [20][21][22]. However, the

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

• Camila S. Pires,
• Daniela H. de Oliveira,
• Maria R. B. Pontel,
• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Diego Alves,
• Raquel G. Jacob and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

• -(phenylselanyl)-1H-pyrazol-5-amine was submitted to an oxidative dehydrogenative coupling to produce a diazo compound confirmed by X-ray analysis. Keywords: diaryl diselenide; diazo compound; 1H-pyrazole; molecular iodine; multicomponent reaction; Introduction Selenium-containing compounds are of great

• Lewis acid to generate the hydrazone intermediate A. Then, hydrazone A undergoes a cyclization reaction followed by an oxidative aromatization to yield 1H-pyrazol-5-amine 5. At the same time, the diaryl diselenide 3 reacts with the molecular iodine to generate an electrophilic selenium species B. The

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• of oxidizing systems such as H2O2/aryl benzyl selenoxide and H2O2/diaryl diselenide is similar to that of m-chloroperbenzoic acid [212][232][233]. The main advantage of these selenium-containing systems is that the catalysts are regenerated and can therefore be used at low loadings [234][235][236

• diselenide system is presented in Table 3 [212]. In the first step of the catalytic cycle of the Baeyer–Villiger oxidation using diaryl diselenide 50 and hydrogen peroxide seleninic acid 51 is generated, which is then oxidized to perseleninic acid 52. Oxidation of the ketone 45 by perseleninic acid 52

• ]. Some results of the oxidation of ketones and aldehydes 45a–c to the corresponding esters 46a–c using the H2O2/aryl benzyl selenoxide system are collected in Table 2 [232]. The oxidation results of ketones 47a,b and aldehydes 47c–e to lactones 48a,b and carboxylic acids 49a–c promoted by the H2O2/diaryl

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

• Yohsuke Kobiki,
• Shin-ichi Kawaguchi,
• Takashi Ohe and
• Akiya Ogawa

Beilstein J. Org. Chem. 2013, 9, 1141–1147, doi:10.3762/bjoc.9.127

• , unlike in the case of diphenyl selenide 3aa (Scheme 2). Additionally, air is entrained in the reaction system, since a test tube with a septum was used in which a needle was inserted. When the reaction of diaryl diselenide with triarylbismuthine was conducted with a strictly sealed tube in Ar atmosphere

• , a bismuth mirror was observed and the yield of 3aa decreased. We assume that the reaction proceeds with bismuth residue getting oxidized. A plausible reaction pathway for the photoinduced reaction of diaryl diselenide with triarylbismuthine is shown in Scheme 3. First, an aryl radical is generated

• from triarylbismuthine by near-UV light irradiation [33][54][55]. The generated aryl radical is captured by diaryl diselenide to produce diaryl selenide and a seleno radical. The seleno radical may dimerize to re-form diselenide. Diphenyl diselenide has its absorption maximum (λmax) at 340 nm (ε = 103