Metal-Free Photoinduced Hydrocyclization of Unactivated Alkenes toward Ring-Fused Quinazolin-4(3H)-ones via Intermolecular Hydrogen Atom Transfer

Organic Letters, Journal Year: 2023, Volume and Issue: 25(10), P. 1683 - 1688

Published: March 8, 2023

A visible-light-induced hydrocyclization of unactivated alkenes was developed using 3CzClIPN as the photocatalyst to generate substituted α-methyldeoxyvasicinones and α-methylmackinazolinones in moderate good yields. An intermolecular hydrogen atom transfer with THF source involved. Mechanism studies indicated that intramolecular addition situ formed aminal radical alkene generated polycyclic quinazolinone.

Language: Английский

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Radical Cascade Cyclization of Alkene‐Tethered Compounds: Versatile Approach towards Ring‐Fused Polycyclic Structures

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(5)

Published: April 8, 2023

Abstract Ring‐fused polycyclic structures widely exist in a myriad of natural products and pharmaceutical molecules. Consequently, the construction such from readily available substrates becomes an important researching topic organic synthesis. Triggered by addition radicals to (activated or unactivated) double bonds alkenes, subsequent intramolecular addition/cyclization leads compounds. Following this procedure, variety functionalized ring‐fused were formed. Great achievements have been witnessed recently. Those works provided efficient, atom economy, operational simple approaches toward versatile alkene‐based substrates. Here, we summarized recent on formation via radical‐triggered cascade reactions alkenes. Construction with no less than 3 fused rings developed during last decade included Review, corresponding mechanisms also discussed.

Language: Английский

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Photoinduced palladium-catalyzed radical addition/cyclization of unactivated alkenes with alkyl halides toward alkylated ring-fused quinazolinones

Journal of Organometallic Chemistry, Journal Year: 2024, Volume and Issue: 1008, P. 123066 - 123066

Published: Feb. 18, 2024

Language: Английский

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Synthesis of 2,3-Fused Quinazolinones via the Radical Cascade Pathway and Reaction Mechanistic Studies by DFT Calculations

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(15), P. 10448 - 10459

Published: July 17, 2023

An efficient radical cascade cyclization of unactivated alkenes toward the synthesis a series ring-fused quinazolinones has been developed in moderate to excellent yields using commercially available ethers, alkanes, and alcohols, respectively, under base-free condition short time without transition metal as catalyst. Notably, transformations can be carried out with advantages broad substrate scope high atomic economy. Density functional theory calculations wavefunction analyses were performed elucidate reaction mechanism.

Language: Английский

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NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

Beilstein Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 19, P. 57 - 65

Published: Jan. 16, 2023

A practical NaI/PPh 3 -catalyzed decarboxylative radical cascade cyclization of N -arylacrylamides with redox-active esters is described, which mediated by visible light irradiation. wide range substrates bearing different substituents and derived from ubiquitous carboxylic acids, including α-amino were synthesized examined under this very mild, efficient, cost effective transition-metal-free synthetic method. These afforded various functionalized oxindoles featuring a C3 quaternary stereogenic center. Mechanistic experiments suggest mechanism.

Language: Английский

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Radical Cascade Cyclization Involving C(sp³)—H Functionalization of Unactivated Cycloalkanes

Chinese Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 42(12), P. 4111 - 4111

Published: Jan. 1, 2022

Unactivated cycloalkane is one of the most extensive natural resources, and it great significance to develop mild efficient strategies achieve C(sp 3 )-H unactivated cycloalkanes.At same time, preparation ring compounds hotspots in organic synthesis medicinal chemistry.Because advantages conditions high reactivity, radical cascade cyclization involving functionalization cycloalkanes can simultaneously meet above requirements synthesize cyclic molecules with potential applications atomic-and stepeconomy manner.In this review, from point view iron catalysis, copper metal-catalyst-free systems, advances recent ten years are summarized.Keywords cycloalkane; functionalization; cyclization; catalytic system尽管被邻位氧、氮等原子活化的 键的官能化 已获得了快速的发展 [2] , 未活化 键官能化的 研究却相对较少, 这主要是由于后者较高的键解离能和 较低的极性所致 [3] .鉴于上述挑战, 化学工作者针对未 活化环烷烃的官能化进行了不懈探索.定向基团配位或 者金属催化的卡宾/氮宾迁移已被广泛应用于未活化环 烷烃 键官能化 [4] 然而这些方法普遍存在对 较高温度的依赖、借助定向基团的辅助或需要使用昂贵 金属催化剂的局限 [5] .因此, 在温和条件下尤其是存在 反应活性更高官能团情况时仍能选择性实现未活化环 烷烃的 官能化成为化学工作者关注的焦点之 一. 自由基反应因具有条件温和、反应活性高、官能团 耐受性优良等特点, 为开发未活化环烷烃 键 官能化提供了新思路 [6] .尤其是, 自由基串联环化已被 证明是一种高效和通用的合成策略, 能高原子和高步骤 经济性地实现未活化环烷烃与不饱和烃之间的反应来 构建各种环状骨架, 为具有环状体系的药物分子和天然 产物合成提供了重要途径 [7] .

Language: Английский

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Photocatalyzed Acylmethylation/Cyclization of Unactivated Alkenes with Sulfoxonium Ylides towards Acylmethylated Polycyclic Quinazolinones

ChemCatChem, Journal Year: 2024, Volume and Issue: unknown

Published: May 16, 2024

Abstract The synthesis of acylmethylatated pyrrolo‐quinazolinones was developed via photo‐induced cascade radical addition/cyclization N ‐(but‐3‐enyl)quinazolin‐4(3 H )‐ones with sulfoxonium ylides using 4CzIPN as the photocatalyst. This approach also suitable for construction piperidino‐quinazolinones. protocol features mild conditions, convenient operation, broad substrate scope and good functional group compatibility.

Language: Английский

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Visible‐Light‐Driven Synthesis of 6‐Aroyl Benzimidazo[1,2‐c]quinazolines from N‐Cyanobenzimidazoles and α‐Keto Acids by Radical Relay Cyclization

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: May 31, 2024

Abstract A diverse array of 6‐aroyl benzimidazo[1,2‐ c ]quinazolines was successfully synthesized using easily obtainable N ‐cyanobenzimidazoles and α‐keto acids, facilitated by photoredox catalysis. mechanistic investigation revealed that this methodology might involve both energy transfer catalytic cycles, generating acyl radicals subsequently promote radical relay cyclization.

Language: Английский

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Radical Reactions in Water

Published: Nov. 8, 2024

The increasing popularity of water as an environmentally friendly solvent in organic synthesis underscores its pivotal role sustainable chemistry. In this chapter, we mainly focus on radical reactions using a reaction medium. literature review presented herein categorizes various studies based distinct catalytic modes and types, aiming to shed light both challenges opportunities burgeoning field.

Language: Английский

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Recent advancements in iodide/phosphine-mediated photoredox radical reactions

Beilstein Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 19, P. 1785 - 1803

Published: Nov. 22, 2023

Photoredox catalysis plays a crucial role in contemporary synthetic organic chemistry. Since the groundbreaking work of Shang and Fu on photocatalytic decarboxylative alkylations 2019, wide range transformations, such as alkylation, alkenylation, cyclization, amination, iodination, monofluoromethylation, have been progressively achieved using combination iodide PPh 3 . In this review, we primarily focus summarizing recent advancements inexpensive readily available iodide/phosphine-mediated photoredox radical transformations.

Language: Английский

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