Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• conditions. The reactions proceed readily in refluxing acidified (pKa = 1–5) ethanol solutions of the amine hydrochlorides to give 2-monosubstituted derivatives of 3H-phenoxazin-3-ones in a moderate yield [10][17]. In the present work, we intended to explore the reaction of 3H-phenoxazin-3-ones with aromatic

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• increase by a factor of 2.3 when the pressure is raised to 2000 atmospheres but the solvent isotope effect ratio is essentially unchanged [21]. The parent benzenesulfonyl chloride and a series of monosubstituted derivatives (p-nitro, m-nitro, p-bromo, p-methoxy, and p-methyl) have had their specific rates

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• disubstituted derivative of cinchona alkaloid–non-methylated CD was developed. The prepared derivative was subsequently tested in an AAA reaction. In contrast to the monosubstituted derivatives, disubstituted CDs should be considered as possible mixtures of regioisomers and pseudoenantiomers [31][32]. Because

• with monosubstituted derivatives at position 6 on the primary rim (Figure 3). Generally, we observed four different regions with the typical signals: the first, well-resolved aromatic region belongs to the quinoline part of the cinchona alkaloid (9.00–7.55 ppm) and to the hydrogen signal of the

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

• -activated acylimidazole derivative was then converted to a β-ketoester containing a two carbon atom-elongated side chain than that of the starting material. A Knorr cyclization of the bifunctional 1,3-dicarbonyl compound with hydrazine and its monosubstituted derivatives in AcOH under microwave heating

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• , Hlavova 8, 128 43, Prague 2, Czech Republic Department of Analytical Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 43, Prague 2, Czech Republic 10.3762/bjoc.13.248 Abstract Monosubstituted derivatives of γ-cyclodextrin (γ-CD) are suitable building blocks for supramolecular polymers

• supramolecular polymers [9] multifunctional molecules are assembled in a regular manner. To avoid branching, monosubstituted CDs are required for a linear supramolecular polymer of CDs with guest groups attached. Monosubstituted derivatives of CDs [10] include three regioisomers, namely 2I-O-, 3I-O-, and 6I-O

p-tert-Butylthiacalix[4]arenes functionalized by N-(4’-nitrophenyl)acetamide and N,N-diethylacetamide fragments: synthesis and binding of anionic guests

• Alena A. Vavilova and
• Ivan I. Stoikov

Beilstein J. Org. Chem. 2017, 13, 1940–1949, doi:10.3762/bjoc.13.188

• therefore block three residual hydroxy groups are usually applied in the synthesis of the monosubstituted derivatives of p-tert-butylthiacalix[4]arene [43]. For the synthesis of the monosubstituted derivative, the bulky N,N-diethylacetamide group able to participate in the formation of hydrogen bonds was

Optimized methods for preparation of 6^I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives

• Eva Bednářová,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2016, 12, 349–352, doi:10.3762/bjoc.12.38

• disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces. Keywords: cyclodextrins; disulfides; monosubstituted derivatives; thiols; Introduction Cyclodextrins (CDs) [1], cyclic oligomers of α-D-glucopyranose, are used for their

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• MW-assisted procedure for the synthesis of 6I-amino-6I-deoxy-β-CD has been reported by Puglisi et al. The reactions were performed in a MW oven (CEM Explorer) for 30 min at 200 W and 85 °C [46]. In the Table 2we compared MW vs conventional procedures in the preparation of several monosubstituted

• derivatives. Besides a slight improvement of formyl and thio derivative yield, the data show a significant reaction rate acceleration. Preparation of persubstituted CD derivatives Selective permodification refers to a complete derivatization of the hydroxy groups in one side of the CD. The selective full

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

• Gabor Benkovics,
• Ondrej Hodek,
• Martina Havlikova,
• Zuzana Bosakova,
• Pavel Coufal,
• Milo Malanga,
• Eva Fenyvesi,
• Andras Darcsi,
• Szabolcs Beni and
• Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

• and ester linkages was already reported by Harada et al. [8][9]. These monosubstituted derivatives formed different types of supramolecular assemblies (dimers, cyclic oligomers, linear polymers) in water depending on the position of the cinnamoyl moiety on the CD rim. It was also experimentally proven