Mesityllithium

Introduction

The use of lithium reagents in organic synthesis is well documented in the literature. [1-3] Amongst the other reagents, mesityllithium has occupied an important place [4-24] because of its non-nucleophilicity, strongly basic nature, clean selective reactivity and easy preparative methods. 2-Bromomesitylene is treated with tert-butyllithium in THF solution, a method that leads to a 1:1 mixture of the reagent and lithium bromide (Scheme 1). [4] [11] [12] For large scale reactions, it may be more convenient to prepare mesityllithium from bromomesitylene and lithium metal. [13-15]

Scheme 1 Preparation of mesityllithium reagent

The highly hindered mesityllithium reagent is monomeric [16] i.e. not aggregated as are most other lithium derivatives. Freshly prepared mesityllithium is normally used, but mesityllithium may be stored, refrigerated, in solution with Et₂O/THF under Ar or N₂.

References

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