BI-OAc-Accelerated C3–H Alkylation of Quinoxalin-2(1H)-ones under Visible-Light Irradiation

Organic Letters, Journal Year: 2020, Volume and Issue: 22(15), P. 5984 - 5989

Published: July 24, 2020

An efficient, photoredox-catalyst-free radical alkylation of quinoxalin-2(1H)-ones has been described. This reaction utilizes 4-alkyl-1,4-dihydropyridines (R-DHPs) as alkyl precursors and acetoxybenziodoxole (BI-OAc) an electron acceptor to undergo single-electron transfer with photoexcited R-DHPs. The benign conditions allow for good compatibility in the scope both synthetic value protocol was also demonstrated by successful functionalization natural products drug-based complex molecules

Language: Английский

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Urea as a Redox-Active Directing Group under Asymmetric Photocatalysis of Iridium-Chiral Borate Ion Pairs

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(46), P. 19462 - 19467

Published: Nov. 5, 2020

The development of a photoinduced, highly diastereo- and enantioselective [3 + 2]-cycloaddition N-cyclopropylurea with α-alkylstyrenes is reported. This asymmetric radical cycloaddition relies on the strategic placement urea cyclopropylamine as redox-active directing group (DG) anion-binding ability use an ion pair, comprising iridium polypyridyl complex weakly coordinating chiral borate ion, photocatalyst. structure anion component catalyst governs reactivity, pertinent structural modification enables high levels catalytic activity stereocontrol. system tolerates range hence offers rapid access to various aminocyclopentanes contiguous tertiary quaternary stereocenters, DG readily removable.

Language: Английский

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Microreaction processes for synthesis and utilization of epoxides: A review

Chemical Engineering Science, Journal Year: 2020, Volume and Issue: 229, P. 116071 - 116071

Published: Aug. 27, 2020

Language: Английский

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Divergent Synthesis of Aziridine and Imidazolidine Frameworks under Blue LED Irradiation

Organic Letters, Journal Year: 2021, Volume and Issue: 23(11), P. 4109 - 4114

Published: May 14, 2021

We develop a visible light-promoted divergent cycloaddition of α-diazo esters with hexahydro-1,3,5-triazines, leading to series aziridine and imidazolidine frameworks in average good yield, by simply changing the reaction media used. It is noteworthy that occurs under sole light irradiation without need for exogenous photoredox catalysts. More significantly, reasonable mechanism was proposed on basis control experiments density functional theory calculation results.

Language: Английский

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Visible Light-Promoted Transformation of Diazo Compounds via the Formation of Free Carbene as Key Intermediate

Chinese Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 41(12), P. 4565 - 4565

Published: Jan. 1, 2021

Carbene is one of the most important synthetic intermediates in organic synthesis.In past few decades, transition-metal catalyzed carbene transfer reactions have made remarkable development.Recently, visible light-promoted transformation diazo compounds through formation free as key intermediate begun to rise.The reaction only need light sole energy source which meets concept green chemistry.Since pioneering works developed by groups Diaves and Zhou, photo-promoted has attracted more attentions.On basis previous work, latest progress this field further improved, mainly focuses on recent new under irradiation contributions reported from Chinese research group.The future development direction, well challenges prospected.

Language: Английский

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Oxime Ether Synthesis through O–H Functionalization of Oximes with Diazo Esters under Blue LED Irradiation

Organic Letters, Journal Year: 2021, Volume and Issue: 23(17), P. 6951 - 6955

Published: Aug. 12, 2021

A green and sustainable oxime ether formation method via the visible-light-promoted O–H functionalization of oximes with diazo esters is described. The reaction occurs under very mild conditions (catalyst- additive-free) a high yield functional group tolerance. When was performed cyclic as solvent (e.g., THF, 1,4-dioxane, tetrahydropyran, ect.), an interesting photochemical three-component product obtained in good yields.

Language: Английский

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Photochemical Synthesis of Succinic Ester-Containing Phenanthridines from Diazo Compounds as 1,4-Dicarbonyl Precursors

Organic Letters, Journal Year: 2022, Volume and Issue: 24(32), P. 6018 - 6023

Published: Aug. 10, 2022

We disclosed herein a straightforward photochemical method for the construction of phenanthridines containing synthetically useful succinate unit. The reaction occurred under visible-light irradiation with cheap eosin Y Na as photoredox catalyst and diazo compound precursor. Under optimal conditions, wide range were obtained in moderate to good yields. Note that units final heterocycles could be easily transformed into many valuable structures, such γ-butyrolactone, dihydrofuran-2(3H)-one, tetrahydrofuran. Mechanistic experiments performed support proposed mechanism.

Language: Английский

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Light driven chemical fixation and conversion of CO2 into cyclic carbonates using transition metals: A review on recent advancements

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 502, P. 215636 - 215636

Published: Dec. 25, 2023

Language: Английский

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Stereoselective Photoredox Catalyzed (3+3) Dipolar Cycloaddition of Nitrone with Aryl Cyclopropane

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(44)

Published: Sept. 13, 2023

Abstract By resorting to the principle of remote activation, we herein demonstrate first photoredox catalyzed (3+3) dipolar cycloaddition nitrones with aryl cyclopropanes. Key fidelity reaction resides in a facile manner substrate activation by single‐electron transfer (SET) oxidation catalysis, and takes place through stepwise cascade encompassing three‐electron‐type nucleophilic substitution triggered cyclopropane ring‐opening diastereoselective 6‐endo‐ trig radical cyclization manifold. The proceeds under mild conditions excellent regio‐ stereoselectivity, nicely complementing well‐developed Lewis acid donor‐acceptor Other merits protocol include wide scope cyclopropanes diversified patterns good functional‐group compatibility. A mechanism involving an cation promoted mode was also proposed supported mechanistic experiments.

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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