Oxidative coupling of alkynes mediated by nitroxyl radicals under Sonogashira conditions and Pd-free catalytic approach to stable radicals of 3-imidazoline family with triple bonds

Vasilevsky, S. F.; Krivenko, Olga L.; Alabugin, Igor V.

doi:10.1016/j.tetlet.2007.09.031

Cited by 9 publications

(1 citation statement)

References 20 publications

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“…10 Following this pioneering study, numerous protocols solely for the Cu-catalyzed Sonogashira coupling have emerged to date, 11 including aqueous, 12 solvent-free, 13 microwave-assisted, 14 and visible-light promoted ones 15 as well as utilizing recyclable heterogeneous catalysts. 16 This approach proved useful and sometimes even indispensable in performing macrocyclizations, 17 the domino construction of a plethora of various heterocycles, 18 assembly of stable organic radicals 19 and supramolecular architectures, 20 and the preparation of natural products and their derivatives ( e.g. carbohydrates, 21 steroids, 22 core structure of terpenoid brownin F, 23 antibiotic anisomycin, 24 rosuvastatin analogs, 25 alkaloids isocryptolepine 26 and lennoxamine, 27 bioactive benzofurans, 28 butenolides, 29 and phthalides 30 ).…”

Section: Introductionmentioning

confidence: 99%

Copper-catalyzed deacetonative Sonogashira coupling

et al. 2022

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Section: Introductionmentioning

confidence: 99%

Copper-catalyzed deacetonative Sonogashira coupling

et al. 2022

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Nitroxides in Synthetic Radical Chemistry

Tansakul

Braslau

2012

Encyclopedia of Radicals in Chemistry, Biology and Materials

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Nitroxides are persistent organic free radicals utilized in synthesis as carbon radical trapping agents and as oxidants. Since nitroxides trap carbon radicals at close to diffusion‐controlled rates, carbon radicals are either trapped directly or undergo fast cyclizations or rearrangements before trapping. The resulting alkoxyamines are typically reduced to the alcohol or oxidized to the ketone. Alkoxyamines bearing radical‐stabilizing groups on the alkyl fragment undergo reversible homolysis on heating, allowing cyclizations or intermolecular olefin additions based on the persistent radical effect. Nitroxides are widely used as oxidants, either by a single electron transfer mechanism or, most commonly, via the oxoammonium salt. Oxoammonium salts oxidize alcohols by two different mechanisms, depending on the pH. Strongly acidic conditions favor oxidation of secondary over primary alcohols, whereas mild acidic or basic conditions give the opposite selectivity. The oxoammonium can be utilized stoichiometrically or catalytically with a primary cooxidant. Optically active nitroxides effect kinetic resolution and desymmetrization. Sulfides, allylic CH bonds, and benzylic ethers also undergo oxidation. Activation of nitroxides by complexation with metals provides an electrophilic oxygen trap for nucleophiles such as enamines and hydride. Electron‐poor nitroxides abstract activated hydrogens, and add to phenols, resulting in quinone formation.

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One‐Pot Tandem Coupling Method for the Short‐Step Formal Synthesis of Riccardin C

Kobatake

Miyoshi

Ueno

2023

Chemistry A European J

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One-pot reactions reduce reagent amounts and circumvent process treatments, such as work-up and purifications in multi-step reactions. In this study, we achieved the formal total synthesis of riccardin C through a one-pot reaction by simultaneously linking four units through two Sonogashira coupling reactions and one Suzuki coupling reaction, followed by reduction and deprotection. Thus, this one-pot method comprised five steps and did not require the purification of intermediate reaction mixtures, which saves resources, such as reagents and solvents, and expedites the work process.

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Oxidative coupling of alkynes mediated by nitroxyl radicals under Sonogashira conditions and Pd-free catalytic approach to stable radicals of 3-imidazoline family with triple bonds

Cited by 9 publications

References 20 publications

Copper-catalyzed deacetonative Sonogashira coupling

Copper-catalyzed deacetonative Sonogashira coupling

Nitroxides in Synthetic Radical Chemistry

One‐Pot Tandem Coupling Method for the Short‐Step Formal Synthesis of Riccardin C

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