The regioselective intermolecular coupling reaction of vindoline with a wide range of substrates including β-ketoesters, β-diketones, β-ketoaldehydes, β-ketonitriles, malononitriles, and β-cyanoesters provides an opportunity for the synthesis of vinblastine analogues containing deep-seated changes in the upper velbanamine subunit. The transition-metal-free hypervalent iodine(III)-promoted intermolecular sp(3)/sp(2) coupling, representing a special class of selective C-H activation with direct carbon-carbon bond formation, proceeds with generation of a quaternary center capable of incorporation of the vinblastine C16' methyl ester and functionalized for subsequent divergent heterocycle introduction.
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http://dx.doi.org/10.1021/ol400135n | DOI Listing |
Chem Commun (Camb)
January 2025
College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
We have developed transition-metal-free synthetic methodologies for dibenzoxazepinones utilizing salicylamides as starting materials and employing two distinct types of successive hypervalent iodine-mediated arylocyclizations. This synthetic protocol encompasses selective phenol -arylation of salicylamides with diaryliodonium salts, followed by electrophilic aromatic amination utilizing chemically or electronically generated hypervalent iodine reagents in the second stage of the process.
View Article and Find Full Text PDFMolecules
December 2024
School of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
The 2-(4-hydroxyphenoxy)benzamide scaffold is frequently found in a variety of bioactive compounds, displaying a broad spectrum of properties, such as antibacterial and antitumor effects. In this study, we developed a new method for synthesizing 2-(4-hydroxyphenoxy)benzamide derivatives from 2-aryloxybenzamide via a PhIO-mediated oxidation reaction. The optimal reaction conditions were established as follows: TFA was used as the solvent, PhIO served as the oxidant with a substrate-to-oxidant ratio of 1:2, and the reaction was conducted at room temperature.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA FCT , 2829-516 Caparica, Portugal.
The reactivity of our recently disclosed hypervalent iodine reagents (HIRs) bearing a benzylamine with in situ-generated sulfenate salts was investigated. Under the studied conditions sulfonamides have been obtained in up to 52% yield. This reaction has been extended to a variety of HIRs and sulfenate salts to explore the different reactivity of these new reagents.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
The rapid reaction between lead iodide (PbI) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular "thruster"-a hypervalent iodine (III) compound with three carbonyl groups and a C-I bond-that possesses coordination and dissociation abilities, enabling programed modulation of perovskite-film growth kinetics.
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December 2024
The Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA.
The hypervalent iodine-mediated formation of steroidal 5/5-spiroiminals and 5/5-spiroaminals from steroidal amines is presented. Under the influence of excess PhI(OAc) and iodine in acetonitrile at 0 °C, steroidal amines smoothly underwent cyclization to give a mixture of 5/5-spiroiminals and 5/5-spiroaminals. This reaction represents the first example of a C-H-activation-mediated formation of a spiroiminal.
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