Enantioselective and Regiodivergent Copper-Catalyzed Electrophilic Arylation of Allylic Amides with Diaryliodonium Salts.

Elise Cahard,Matthew J. Gaunt,Matthieu Tissot,Henry P. J. Male

doi:10.1021/jacs.5b03937

Elise Cahard, Matthew J. Gaunt + Show 2 more

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https://doi.org/10.1021/jacs.5b03937

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Abstract

A catalytic enantioselective and regiodivergent arylation of alkenes is described. Chiral copper(II)bisoxazoline complexes catalyze the addition of diaryliodonium salts to allylic amides in excellent ee. Moreover, the arylation can be controlled by the electronic nature of the diaryliodonium salt enabling the preparation of nonracemic diaryloxazines or β,β′-diaryl enamides.

Highlights

The catalytic asymmetric addition of carbon electrophiles to alkenes represents a strategically important bond-forming process
Over the last 7 years our laboratory has explored the novel reactivity of a putative copper(III)-aryl species as an aromatic electrophile equivalent.[5−7] These high oxidation state organometallics can be catalytically generated by the combination of simple copper complexes and diaryliodonium salts, and we have shown that a range of latent nucleophiles undergo site-selective arylation reactions to form synthetically versatile products
In addition to these studies, our group,6d as well as that of MacMillan,7b,c has shown that copper−bisoxazoline complexes can function as excellent catalysts for enantioselective arylation reactions between electron-rich alkenes and diaryliodonium salts

Summary

Introduction

The catalytic asymmetric addition of carbon electrophiles to alkenes represents a strategically important bond-forming process. In addition to these studies, our group,6d as well as that of MacMillan,7b,c has shown that copper−bisoxazoline complexes can function as excellent catalysts for enantioselective arylation reactions between electron-rich alkenes and diaryliodonium salts (eq 1). Chiral copper(II)bisoxazoline catalysts impart high enantioselectivity in an oxy-arylation process wherein arylation takes place at alkene position proximal to the carbonyl, to form 1,3-oxazines.

Results

Conclusion