Acoplamiento electrorreductivo olefino-cetónico

Pengfei Hu1,2, Byron K Peters1,2, Christian A Malapit3,2

  • 1Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla 92037, California, United States.

Resumen

Este estudio introduce un nuevo método electroquímico en el que las cetonas actúan como nucleófilos para sintetizar alcoholes terciarios a partir de olefinas. Esta técnica fácil de usar ofrece una alternativa escalable y tolerante al aire y al agua a las adiciones tradicionales de Grignard.

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α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview

The pinacol and McMurry reactions involve the reductive coupling of ketones or aldehydes. Similarly, the bimolecular reductive coupling of two ester molecules in the presence of sodium metal in an aprotic solvent yields an α-hydroxy ketone product. The α-hydroxy ketone is also called acyloin, so the reaction is referred to as ‘acyloin condensation.’
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Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview01:27

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Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.
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Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction01:22

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

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Aldol Condensation with β-Diesters: Knoevenagel Condensation01:27

Aldol Condensation with β-Diesters: Knoevenagel Condensation

The Knoevenagel condensation is an aldol-type reaction involving the condensation of aldehydes or ketones with active methylene compounds such as β-diesters to produce substituted olefins.
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Acid-Catalyzed Aldol Addition Reaction01:15

Acid-Catalyzed Aldol Addition Reaction

The aldol reaction of a ketone under acidic conditions successfully forms an unsaturated carbonyl as the final product instead of an aldol. The acid-catalyzed aldol reaction is depicted in Figure 1.
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C–C Bond Cleavage: Retro-Aldol Reaction00:57

C–C Bond Cleavage: Retro-Aldol Reaction

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In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
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