Highly Chemoselective and Enantiospecific Suzuki–Miyaura Cross-Couplings of Benzylic Organoboronic Esters

This paper is dedicated to Professor Scott E. Denmark, with thanks for his mentorship, his dedication to excellence and his extensive contributions­ to science.

Abstract

The use of potassium carbonate in addition to silver oxide­ is shown to increase the enantiospecificity of the Suzuki–Miyaura­ cross-coupling reaction of chiral secondary benzylic boronic esters. From mechanistic studies, it is shown that the reaction is compatible with Mizoroki–Heck coupling partners, even when they are present in considerable excess. This unique chemoselectivity provides the opportunity to carry out sequential reactions.

Key words

Suzuki - cross-coupling - palladium - chiral - enantiospecific

• References

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For an example of a system where a Mizoroki–Heck reaction occurs to the exclusion of Suzuki–Miyaura coupling, see:
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