Preparation of Vinylic Lithium Reagents from Silyl Enolates of Alkyl Aryl Ketones Using Lithium Arenide

The preparation of vinylic lithium reagents from vinylic halides is a common practice in organic synthesis. However, the preparation of vinylic halides is not always straightforward. In this study, we propose the use of silyl enolates of alkyl aryl ketones as a readily available and efficient alternative for generating vinylic lithium species. Treatment of triisopropylsilyl enolates of alkyl aryl ketones with lithium naphthalenide or lithium 4,4'-di-t-butylbiphenylide affords the corresponding vinylic lithium species. This preparation represents a reductive transformation of electron-rich silyl enolates, which had remained unexplored. This process provides an alternative to the Shapiro reaction and has great potential for various applications in organic synthesis.

Automated summary

The preparation of vinylic lithium reagents from vinylic halides is common in organic synthesis, but not always easy. This study proposes a new method using silyl enolates of alkyl aryl ketones, which provides readily available and efficient vinylic lithium species. The reductive transformation of electron-rich silyl enolates has significant potential for various applications in organic synthesis, serving as an alternative to the Shapiro reaction.