Photocatalytic Vicinal Aminopyridylation of Methyl Ketones by a Double Umpolung Strategy

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(40), P. 17511 - 17516

Published: June 30, 2020

A photocatalytic double umpolung strategy for the vicinal aminopyridylation of ketones was developed using pyridinium N-N ylides. The inversion polarity ylides by single-electron oxidation successfully enables radical-mediated 1,3-dipolar cycloadditions with enolsilanes formed in situ from ketones, followed homolytic cleavage bond. Intriguingly, nucleophilic amino and electrophilic pyridyl groups can be installed at α-position carbonyl carbon, respectively, which are typically inaccessible their innate polarity-driven reactivity. This method accommodates a broad scope, utility further demonstrated late-stage functionalization complex biorelevant molecules. Moreover, applied to enamides.

Language: Английский

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Shining Light on C−S Bonds: Recent Advances in C−C Bond Formation Reactions via C−S Bond Cleavage under Photoredox Catalysis

Chemistry - An Asian Journal, Journal Year: 2020, Volume and Issue: 15(22), P. 3637 - 3659

Published: Sept. 29, 2020

In recent years, photoredox catalysis has been proved to be a significant and powerful strategy for the activation formation of different chemical bonds. general sense, these approaches rely on generation active radical species enabled by light from various precursors via cleavage corresponding bonds, like C-H bond, C-N C-O C-C C-halo C-S bond other C-heteroatom At same time, generated intermediates can used construction new this review, we highlight C-centered radicals through bonds their application in generally pathways. A range substrates containing are discussed overview expedite progress its subsequent functionalization under catalysis.

Language: Английский

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A Rational Approach to Organo‐Photocatalysis: Novel Designs and Structure‐Property Relationships

Angewandte Chemie, Journal Year: 2020, Volume and Issue: 133(3), P. 1096 - 1111

Published: June 22, 2020

Abstract Organic photocatalysts are emerging as viable and more sustainable tools than metal complexes. Recently, the field of organo‐photocatalysis has experienced an explosion in terms applications, redesign well‐established systems, identification novel scaffolds. A rational approach to structural modification different is key accessing unprecedented reactivity, while improving their catalytic performances. We herein discuss concepts underpinning scaffold some most recently used analyze how specific changes alter physicochemical redox properties.

Language: Английский

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Generation of Functionalized Alkyl Radicals via the Direct Photoexcitation of 2,2′-(Pyridine-2,6-diyl)diphenol-Based Borates

Organic Letters, Journal Year: 2021, Volume and Issue: 23(15), P. 5865 - 5870

Published: July 8, 2021

A new type of alkylborate was developed for the purpose generating radicals via direct photoexcitation. These borates were prepared using 2,2′-(pyridine-2,6-diyl)diphenol as a tridentate ligand together with organoboronic acids or potassium trifluoroborates. The ready availability organoboron compounds is significant advantage this photoexcitation protocol. excited states these can also serve strong reductants, enabling various transformations.

Language: Английский

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Phenolate anion-catalyzed direct activation of inert alkyl chlorides driven by visible light

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(22), P. 6364 - 6370

Published: Jan. 1, 2021

A photochemical activation of inert alkyl chlorides catalyzed by phenolate anions was developed for C–O bond formation, dehalogenation, and cyclization under mild conditions.

Language: Английский

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