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. 2020 Jul 24;10(46):27874-27883.
doi: 10.1039/d0ra05768a. eCollection 2020 Jul 21.

Preparation and facile addition reactions of iminium salts derived from amino ketene silyl acetal and amino silyl enol ether

Makoto Shimizu  1   2 , Shingo Hata  2 , Koichi Kondo  2 , Kazuhiro Murakami  2 , Isao Mizota  2 , Yusong Zhu  1
Affiliations

Preparation and facile addition reactions of iminium salts derived from amino ketene silyl acetal and amino silyl enol ether

Makoto Shimizu et al. RSC Adv. .

Abstract

While iminium salts generated by the oxidation of amino ketene silyl acetals show intriguing reactivities to give useful γ-oxo-α-amino esters via reactions with silyl enol ethers in good yields, new iminium salts are also prepared by the oxidation of amino silyl enol ethers. They undergo facile addition reaction with various nucleophiles to give α-amino ketone derivatives in good yields.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Scheme 1
Scheme 1. Previous and present works.
Scheme 2
Scheme 2. Possible transition state models.
Scheme 3
Scheme 3. Generation of a new iminium salt.
Scheme 4
Scheme 4. Preparation of the amino silyl enol ether 5.
Scheme 5
Scheme 5. Proposed reaction pathways.
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    1. We have already reported the formation of the iminium salt by 1H and 13C NMR spectra and a possible ionic mechanism by the ineffectiveness of radical scavengers.