Merging radical-polar crossover/cycloisomerization processes: access to polyfunctional furans enabled by metallaphotoredox catalysis
- 1 February 2021
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Organic Chemistry Frontiers
- Vol. 8 (8), 1732-1738
- https://doi.org/10.1039/d0qo01472a
Abstract
With the radical derived from alkyl silicates or 4-alkyl-1,4-dihydropyridines as the surrogate for the nucleophile, the cyclisation of 2-(1-alkynyl)-2-alken-1-ones proceeds smoothly via consecutive reductive radical-polar crossover and cycloisomerization processes enabled by dual photoredox–copper catalysis. Both single-electron oxidation and reduction occur between the photocatalyst and radical precursor/adduct radical, generating the enolate ion without the need for a base and an exogenous oxidant–reductant. In contrast to the reported transition-metal catalysed cyclisation with the oxonium ion as the key intermediate, the nucleophilic attack of enolate-oxygen on the copper coordinated alkyne was proposed for this dual catalysis. This new methodology for the preparation of polyfunctional furans features mild conditions, a broad substrate scope, and good functional group tolerance.Keywords
Funding Information
- Natural Science Foundation of Zhejiang Province (LY20B020008)
- Natural Science Foundation of Ningbo (2019A610130, 2019A610203, 2015A610278)
- Science and Technology Innovation 2025 Major Project of Ningbo (2019B10112)
This publication has 62 references indexed in Scilit:
- Reductive radical-initiated 1,2-C migration assisted by an azidyl groupChemical Science, 2020
- Reductive dearomative arylcarboxylation of indoles with CO2 via visible-light photoredox catalysisNature Communications, 2020
- Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and BeyondJournal of the American Chemical Society, 2020
- Visible-Light-Driven Reductive Carboarylation of Styrenes with CO2 and Aryl HalidesJournal of the American Chemical Society, 2020
- Catalytic Asymmetric Radical–Polar Crossover HydroalkoxylationJournal of the American Chemical Society, 2019
- Transition metal-free phosphonocarboxylation of alkenes with carbon dioxide via visible-light photoredox catalysisNature Communications, 2019
- Reductive Cross-Coupling of Aldehydes and Imines Mediated by Visible Light Photoredox CatalysisOrganic Letters, 2018
- Radical-polar crossover reactions of vinylboron ate complexesScience, 2017
- Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic SynthesisChemical Reviews, 2013
- Tetrathiafulvalene as a catalyst for radical–polar crossover reactionsJournal of the Chemical Society, Chemical Communications, 1993