Direct catalytic asymmetric addition of allyl cyanide to ketones via soft lewis acid/hard brønsted base/hard lewis base catalysis

Ryo Yazaki, Naoya Kumagai, Masakatsu Shibasaki

Research output: Contribution to journalArticle

82 Citations (Scopus)

Abstract

We report that a hard Lewis base substantially affects the reaction efficiency of direct catalytic asymmetric γ-addition of allyl cyanide (1a) to ketones promoted by a soft Lewis acid/hard Brønsted base catalyst. Mechanistic studies have revealed that Cu/(R,R)-Ph-BPE and Li(OC 6H4-p-OMe) serve as a soft Lewis acid and a hard Brønsted base, respectively, allowing for deprotonative activation of 1a as the rate-determining step. A ternary catalytic system comprising a soft Lewis acid/hard Brønsted base and an additional hard Lewis base, in which the basicity of the hard Brønsted base Li(OC6H4-p-OMe) was enhanced by phosphine oxide (the hard Lewis base) through a hard-hard interaction, outperformed the previously developed binary soft Lewis acid/hard Brønsted base catalytic system, leading to higher yields and enantioselectivities while using one-tenth the catalyst loading and one-fifth the amount of 1a. This second-generation catalyst allows efficient access to highly enantioenriched tertiary alcohols under nearly ideal atom-economical conditions (0.5-1 mol % catalyst loading and a substrate molar ratio of 1:2).

Original languageEnglish
Pages (from-to)5522-5531
Number of pages10
JournalJournal of the American Chemical Society
Volume132
Issue number15
DOIs
Publication statusPublished - Apr 21 2010
Externally publishedYes

Fingerprint

Lewis Bases
Lewis Acids
Cyanides
Ketones
Catalysis
Catalysts
phosphine
Acids
Enantioselectivity
Alkalinity
Oxides
Alcohols
Chemical activation
Atoms
allyl cyanide
Substrates

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Direct catalytic asymmetric addition of allyl cyanide to ketones via soft lewis acid/hard brønsted base/hard lewis base catalysis. / Yazaki, Ryo; Kumagai, Naoya; Shibasaki, Masakatsu.

In: Journal of the American Chemical Society, Vol. 132, No. 15, 21.04.2010, p. 5522-5531.

Research output: Contribution to journalArticle

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