Sulfoxide-mediated oxidative cross-coupling of phenols.

Zhen He,Gregory J P Perry,David J Procter

doi:10.1039/c9sc05668h

Zhen He, Gregory J P Perry + Show 1 more

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https://doi.org/10.1039/c9sc05668h

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Abstract

A metal-free, oxidative coupling of phenols with various nucleophiles, including arenes, 1,3-diketones and other phenols, is reported. Cross-coupling is mediated by a sulfoxide which inverts the reactivity of the phenol partner. Crucially, the process shows high selectivity for cross-versus homo-coupling and allows efficient access to a variety of aromatic scaffolds including biaryls, benzofurans and, through an iterative procedure, aromatic oligomers.

Highlights

Metal-catalyzed cross-coupling, involving an aryl halide and an organometallic partner, is a powerful tool for biaryl synthesis (Scheme 1A).[1]
Metal-free cross-coupling of phenols has been described, most notably using electroorganic synthesis[7] or hypervalent iodine reagents,[8] amongst other approaches[9] (Scheme 1D)
We proposed that sulfoxides[10,11] could be used to invert the reactivity of a phenol partner, providing an alternative approach to their oxidative coupling (Scheme 1E)

Summary

Introduction

Metal-catalyzed cross-coupling, involving an aryl halide and an organometallic partner, is a powerful tool for biaryl synthesis (Scheme 1A).[1]. (C and D) Metal-free, oxidative coupling of phenols. We proposed that sulfoxides[10,11] could be used to invert the reactivity of a phenol partner, providing an alternative approach to their oxidative coupling (Scheme 1E). We describe the metal-free, oxidative cross-coupling of phenols with various carbon nucleophilic partners, including other phenols, arenes, and 1,3-diketones (Scheme 1E).

Results

Conclusion