Dual nickel and Lewis acid catalysis for cross-electrophile coupling: the allylation of aryl halides with allylic alcohols

Xue-Gong Jia,Jicheng Duan,Xing-Zhong Shu,Peng Guo

doi:10.1039/c7sc03140h

Abstract

Controlling the selectivity in cross-electrophile coupling reactions is a significant challenge, particularly when one electrophile is much more reactive. We report a general and practical strategy to address this problem in the reaction between reactive and unreactive electrophiles by a combination of nickel and Lewis acid catalysis. This strategy is used for the coupling of aryl halides with allylic alcohols to form linear allylarenes selectively. The reaction tolerates a wide range of functional groups (e.g. silanes, boronates, anilines, esters, alcohols, and various heterocycles) and works with various allylic alcohols. Complementary to most current routes for the C3 allylation of an unprotected indole, this method provides access to C2 and C4-C7 allylated indoles. Preliminary mechanistic experiments reveal that the reaction might start with an aryl nickel intermediate, which then reacts with Lewis acid activated allylic alcohols in the presence of Mn.

Highlights

Selective cross-electrophile coupling has recently emerged as an increasingly popular approach for constructing C–C bonds.1 The reaction achieves the union of two different bench-stable electrophiles and avoids using air and/ or moisture sensitive organometallic reagents (RMgX, RZnX, RSnR03, RB(OH)2, etc.).2 Unlike in conventional cross-coupling, where the selectivity is controlled by the oxidative addition of an electrophile and transmetallation of a nucleophile, generally both electrophiles will compete for oxidative addition at the catalyst in cross-electrophile coupling
We report a general and practical strategy to address this problem in the reaction between reactive and unreactive electrophiles by a combination of nickel and Lewis acid catalysis
We have reported a dual nickel and Lewis acidcatalyzed allylation of aryl halides with allylic alcohols

Summary

Introduction

Selective cross-electrophile coupling has recently emerged as an increasingly popular approach for constructing C–C bonds.1 The reaction achieves the union of two different bench-stable electrophiles (aryl/alkyl halides, etc.) and avoids using air and/ or moisture sensitive organometallic reagents (RMgX, RZnX, RSnR03, RB(OH)2, etc.).2 Unlike in conventional cross-coupling, where the selectivity is controlled by the oxidative addition of an electrophile and transmetallation of a nucleophile, generally both electrophiles will compete for oxidative addition at the catalyst in cross-electrophile coupling. This strategy is used for the coupling of aryl halides with allylic alcohols to form linear allylarenes selectively.

Results

Conclusion