Highly Chemoselective Stoichiometric Alkylation of Ketones with Grignard Reagent Derived Zinc(II) Ate Complexes

Abstract

A highly chemoselective alkylation of ketones with Grignard reagent derived stoichiometric zinc(II) ate complexes was developed. Zinc(II) ate complexes are readily prepared at room temperature within one hour in situ from ZnCl₂ and Grignard reagents without unstable alkyllithium reagents. The desired tertiary alcohols were obtained in much improved yields due to the minimization of background reactions with free Grignard reagents.

Key words

ate complex - Grignard reagent - ketone - tertiary alcohol - zinc

References

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9

In general, for aliphatic ketones, in sharp contrast to aromatic ketones, even stoichiometric zinc(II) ate reagents provided small improvements for selective alkylations.