Nickel-catalyzed migratory alkyl-alkyl cross-coupling reaction.

Yangyang Li,Lei Zhu,Yuqiang Li,Long Peng,Guoyin Yin,Dong Wu

doi:10.1039/d0sc03217d

Abstract

The selective cross-coupling of activated electrophiles with unactivated ones has been regarded as a challenging task in cross-electrophile couplings. Herein we describe a migratory cross-coupling strategy, which can overcome this obstacle to access the desired cross-coupling products. Accordingly, a selective migratory cross-coupling of two alkyl electrophiles has been accomplished by nickel catalysis. Remarkably, this alkyl–alkyl cross-coupling reaction provides a platform to prepare 2°–2° carbon–carbon bonds from 1° and 2° carbon coupling partners. Preliminary mechanistic studies suggest that chain-walking occurs at both alkyl halides in this reaction, thus a catalytic cycle with the key step involving two alkylnickel(ii) species is proposed for this transformation.

Highlights

Selective cross-coupling of two electrophiles has been developed into a general procedure to construct carbon–carbon bonds in recent years, owing to their advantage in avoiding handling of air and moisture-sensitive metal reagents.[1]
A selective migratory cross-coupling of two alkyl electrophiles has been accomplished by nickel catalysis
An elegant dual metal cooperative catalysis strategy was introduced by the Weix group,[4] which enables the cross-coupling of two sp2carbon electrophiles or an sp2-carbon electrophile with an sp3carbon electrophile

Summary

Introduction

Selective cross-coupling of two electrophiles has been developed into a general procedure to construct carbon–carbon bonds in recent years, owing to their advantage in avoiding handling of air and moisture-sensitive metal reagents.[1]. Generally speaking, the selective cross-couplings of unactivated electrophiles with activated ones have still been regarded as an invincible task in this arena to date. We report a migratory strategy to break the above obstacle to access the products of crosscoupling of unactivated electrophiles with activated ones (Scheme 1b), and achieve a benzylic selective alkyl–alkyl crosscoupling reaction under mild conditions (Scheme 1c). This strategy provides a platform to construct 2– 2 carbon–carbon bonds from 1 and 2 carbon partners. Scheme 1 Nickel-catalyzed migratory cross-coupling of alkyl electrophiles

Results and discussion

Conclusions

Reviews on chain-walking