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?-Selective Reductive Coupling of Alkenylpyridines with Aldehydes and Imines via Synergistic Lewis Acid/Photoredox Catalysis.

ABSTRACT: Umpolung (polarity reversal) strategies of aldehydes and imines have dramatically expanded the scope of carbonyl and iminyl chemistry by facilitating reactions with non-nucleophilic reagents. Herein, we report the first visible light photoredox-catalyzed ?-selective reductive coupling of alkenylpyridines with carbonyl or iminyl derivatives with the aid of a Lewis acid co-catalyst. Our process tolerates complex molecular scaffolds (e.g., sugar, natural product, and peptide derivatives) and is applicable to the preparation of compounds containing a broad range of heterocyclic moieties. Mechanistic investigations indicate that the key step involves single-electron-transfer reduction of aldehydes or imines followed by the addition of resulting ketyl or ?-aminoalkyl radicals to Lewis acid-activated alkenylpyridines.

SUBMITTER: Lee KN

PROVIDER: S-EPMC5623169 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

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β-Selective Reductive Coupling of Alkenylpyridines with Aldehydes and Imines via Synergistic Lewis Acid/Photoredox Catalysis.

Lee Katarzyna N KN Lei Zhen Z Ngai Ming-Yu MY

Journal of the American Chemical Society 20170330 14

Umpolung (polarity reversal) strategies of aldehydes and imines have dramatically expanded the scope of carbonyl and iminyl chemistry by facilitating reactions with non-nucleophilic reagents. Herein, we report the first visible light photoredox-catalyzed β-selective reductive coupling of alkenylpyridines with carbonyl or iminyl derivatives with the aid of a Lewis acid co-catalyst. Our process tolerates complex molecular scaffolds (e.g., sugar, natural product, and peptide derivatives) and is app ...[more]

PMID: 28358497

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