Copper‐Mediated Direct and Selective C−H Thiolation of Quinazolinones

Sarkar, Writhabrata; Mishra, Aniket; Bhowmik, Arup; Deb, Indubhusan

doi:10.1002/ajoc.201900199

Cited by 11 publications

(2 citation statements)

References 76 publications

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“…Various aromatic and aliphatic diselenides efficiently react with pyridopyrimidin-4-ones, containing electron-donating Quinazolinones 191 are sulfenylated with disulfides 192 with the use of Cu(OAc) 2 and p-benzoquinone (Scheme 83). [217] The reaction proceeds in DCE at 120 °C under an inert atmosphere. Both aromatic and aliphatic disulfides can be used without loss of efficiency.…”

Section: Reactions With the Formation Of Cà S And Cà Se Bondsmentioning

confidence: 99%

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

et al. 2023

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In the last decade, free radicals have found a wide application in functionalization of unsaturated compounds, such as alkenes, alkynes, and arenes, via the free-radical addition to carbon-carbon π-bonds. In these processes, intermolecular free-radical attack on the aromatic substrates represents a challenge due to relatively high resistance of aromatic π-system to addition reactions in comparison to alkene C=C bonds. The free-radical functionalization of heterocycles is especially interesting due to the diversity of their structures and chemical properties as well as their importance for medicinal chemistry, agrochemistry, and materials science. Addition of C-centered radicals to heterocycles is widely known as the Minisci-type reactions and well-reviewed. In this paper, we have summarized the main achievements in less explored group of processes: functionalization of heterocycles by intermolecular addition of heteroatom-centered radicals (O-, N-, S-/Se-, and P-radicals) with the emphasis on the papers published after 2010. Literature analysis revealed the strong trend towards the usage of electrochemistry and photoredox-catal-ysis for the generation of free radicals in recent years. The remaining fundamental problem in this field is the lack of strong experimental support for the proposed mechanisms and frequent existence of several plausible reaction pathways. The progress in mechanistic studies can significantly improve the prediction of optimal reaction conditions depending on the substrates structure. 1. Introduction 2. Radical Functionalization of Heterocycles 2.1. Reactions with the Formation of CÀ O Bonds 2.2. Reactions with the Formation of CÀ N Bonds 2.3. Reactions with the Formation of CÀ S and CÀ Se Bonds 2.4. Reactions with the Formation of CÀ P Bonds 3. Conclusions

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Section: Reactions With the Formation Of Cà S And Cà Se Bondsmentioning

confidence: 99%

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

et al. 2023

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“…Very recently, our group has reported a unique iridium-catalyzed diastereoselective spiroannulation of cyclic N- sulfonyl ketimines with nitroalkenes . Taking account of the rare employment of both 2 H -1,4-benzoxazines and nitroolefins and inspired by our persistent research endeavors for the development of sustainable synthesis of functionalized heterocycle aided by transition-metal-catalyzed C–H functionalization, we herein report a rhodium-catalyzed highly selective and efficient C–H functionalization/annulation cascade under mild and redox-neutral conditions for the synthesis of nitro-substituted spiro 2,3-dihydro-1,4-benzoxazines.…”

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Diastereoselective Spirocyclization of Benzoxazines with Nitroalkenes via Rhodium-Catalyzed C–H Functionalization/Annulation Cascade under Mild Conditions

et al. 2020

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A Rh(III)-catalyzed [3 + 2] annulation of benzoxazines with nitroolefins that proceeds via redox-neutral C–H functionalization has been demonstrated, leading to the novel class of spirocycles in a single step. The construction of three continuous stereogenic centers has been achieved starting from easily accessible achiral substrates in an atom-efficient manner under mild reaction conditions. A broad range of pharmaceutically relevant nitro substituted spirocyclic 2,3-dihydro-1,4-benzoxazine derivatives has been synthesized in good to excellent yields with high diastereoselectivity.

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Diastereoselective Spirocyclization via Intramolecular C(sp³)−H Bond Functionalization Triggered by Sequential [1,5]‐Hydride Shift/Cyclization Process: Approach to Spiro‐tetrahydroquinolines

et al. 2020

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A direct synthesis of spiro[5.5]and [5.4]‐tetrahydroquinolines has been developed through C(sp3)−H bond functionalization triggered by sequential [1,5]‐ hydride shift /cyclization sequence using ortho amino benzaldehydes and active methylene compounds such as 2‐coumaranone, 4‐hydroxycoumarin, 3‐coumaranone, and 3‐isochromanone. This protocol provides a Lewis acid catalyst‐free straight forward one‐pot reaction in cases of 2‐coumaranone and 4‐hydroxycoumarin, Lewis acid‐catalyzed stepwise reaction for 3‐coumaranone and 3‐isochromanone to access a wide range of spiro‐heterocycles in excellent to good yields and diastereoselectivity.

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Copper‐Mediated Direct and Selective C−H Thiolation of Quinazolinones

Cited by 11 publications

References 76 publications

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

Diastereoselective Spirocyclization of Benzoxazines with Nitroalkenes via Rhodium-Catalyzed C–H Functionalization/Annulation Cascade under Mild Conditions

Diastereoselective Spirocyclization via Intramolecular C(sp³)−H Bond Functionalization Triggered by Sequential [1,5]‐Hydride Shift/Cyclization Process: Approach to Spiro‐tetrahydroquinolines

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Copper‐Mediated Direct and Selective C−H Thiolation of Quinazolinones

Cited by 11 publications

References 76 publications

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

Diastereoselective Spirocyclization of Benzoxazines with Nitroalkenes via Rhodium-Catalyzed C–H Functionalization/Annulation Cascade under Mild Conditions

Diastereoselective Spirocyclization via Intramolecular C(sp3)−H Bond Functionalization Triggered by Sequential [1,5]‐Hydride Shift/Cyclization Process: Approach to Spiro‐tetrahydroquinolines

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Diastereoselective Spirocyclization via Intramolecular C(sp³)−H Bond Functionalization Triggered by Sequential [1,5]‐Hydride Shift/Cyclization Process: Approach to Spiro‐tetrahydroquinolines