Alkyl radicals from diacyl peroxides: metal-/base-/additive-free photocatalytic alkylation of N-heteroaromatics

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(20), P. 7971 - 7977

Published: Jan. 1, 2023

Alkyl diacyl peroxides were demonstrated to be efficient alkylating reagents for the visible-light-induced 4CzIPN-catalyzed direct C–H alkylation of N -heteroaromatics.

Language: Английский

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Recent Advances in Cyclization Reactions of 1,6‐Enynes

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(6), P. 1220 - 1268

Published: Jan. 22, 2024

Abstract Elaborated molecular architectures, specifically those bearing one or more carbon stereocenters, stand as an important class of carbocyclic and heterocyclic frameworks because they are frequently occurring core structures in numerous natural products biologically active pharmaceutical molecules. Over the past few decades, development versatile synthetic approaches via cascade cyclization reactions 1,6‐enynes for construction a series fused spiro compounds has been focus great deal research initiatives. These synthesis strategies peculiarly fascinating context assembly wide array molecules, products, agrochemicals, functional materials. In this review, recent developments transformations with diverse coupling reagents summarized since 2018, which could be divided into five categories: 1) Introduction; 2) Transition metal catalyzed 1,6‐enynes; 3) Metal‐free 4) Visible‐light‐induced 5) Electrocatalytic 1,6‐enynes.

Language: Английский

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Base-Promoted Regioselective Annulation of Pyridinium Ylides and Bromoalkynes for the Chemodivergent Synthesis of Indolizines

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

A base-promoted regioselective formal [3 + 2] annulation of pyridinium ylides with bromoalkynes is reported, producing a series substituent-diverse indolizines in generally good yields. mild K2CO3-promoted three-component cyclization and at 2:1 molar ratio delivered C2-acylmethylated indolizines, whereas C2-brominated were generated starting from bearing strong electron-withdrawing groups the unit by using 2,2,6,6-tetramethyl-1-piperidinyloxy as dehydrogenating reagent. The current synthetic methodology offers controllable modular approach to access different substitution patterns, featuring wide substrate scope, functional group compatibility, complete regioselectivity without demand any transition-metal catalysts.

Language: Английский

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Photocatalytic Multicomponent Annulation of Amide-Anchored 1,7-Diynes Enabled by Deconstruction of Bromotrichloromethane

Molecules, Journal Year: 2024, Volume and Issue: 29(4), P. 782 - 782

Published: Feb. 8, 2024

We present the first example of visible-light-mediated multicomponent annulation 1,7-diynes by taking advantage quadruple cleavage olf carbon-halogen bonds BrCCl3 to generate a C1 synthon, which was adeptly applied preparation skeletally diverse 3-benzoyl-quinolin-2(1H)-one acetates in moderate good yields. Controlled experiments demonstrated that H2O acted as both oxygen and hydrogen sources, gem-dichlorovinyl carbonyl compound exhibited critical intermediate this process. The mechanistic pathway involves Kharasch-type addition/6-exo-dig cyclization/1,5-(SN”)-substitution/elimination/binucleophilic 1,6-addition/proton transfer/tautomerization sequence.

Language: Английский

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Metal-Free Synthesis of 2H-Indazole Skeletons by Photochemistry or Thermochemistry

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(17), P. 12341 - 12356

Published: Aug. 15, 2023

A simple and tuned synthesis of a 2H-indazole skeleton under metal-free conditions was developed. Under visible-light irradiation at room temperature, 2-((aryl/alkyl/H)ethynyl))aryltriazenes reacted with arylsulfinic acids to afford 3-functionalized 2H-indazoles without extra photocatalyst via an electron donor-acceptor complex. In the presence acid, 2-(ethynyl)aryltriazenes underwent intramolecular oxidation/cyclization provide 2H-indazole-3-carbaldehydes 50 °C in air.

Language: Английский

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Visible-Light-Mediated Radical Hydroalkylative Cyclization of 1,6-Enynes

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(23), P. 16639 - 16643

Published: Nov. 17, 2023

A radical hydroalkylative cyclization approach accessing various alkenyl heterocyclic compounds was developed using dimethyl malonate and 1,6-enynes in the presence of visible-light photoredox catalysis. The use Ir(dtbbpy)(ppy)2PF6 as a photosensitizer enables carbon atom formation initiates cascade reaction under mild conditions.

Language: Английский

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Visible Light-promoted Preparation of 2,3-Dihydrobenzofurans and Coumaranones

Current Organic Chemistry, Journal Year: 2024, Volume and Issue: 28(11), P. 830 - 843

Published: April 25, 2024

Abstract: 2,3-Dihydrobenzofuran and coumaranone are readily available in numerous naturally occurring compounds. They mostly exist plenty of food plants medicinal plants. Such compounds constitute a series flavor components bioactive molecules. Their preparation has been an attractive field research. In the past few decades, great efforts have made 2,3-dihydrobenzofuran structure through both metal-catalyzed organocatalyzed ways. Visible light-promoted reactions sprang up early 21st century represent green manner transformations. Under irradiation visible light, radicals could be generated under milder conditions. Thus, lightpromoted spread widely chemical synthesis. recent years, developed by different groups, including intramolecular intermolecular reactions. The benign reaction conditions allow better functional group-tolerance lead to diverse structures. Several reviews on synthesis 2,3- dihydrobenzofuran reported. However, approaches such structures not well reviewed. Our review will cover literature that reported discovery 2,3-dihydrobenzofuran, attempting summarize existing methods provide guidance chemists present challenges.

Language: Английский

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