Hydroalkylation of unactivated olefins with C(sp³)─H compounds enabled by NiH-catalyzed radical relay.

Abstract

The hydroalkylation reaction of olefins with alkanes is a highly desirable synthetic transformation toward the construction of C(sp³)─C(sp³) bonds. However, such transformation has proven to be challenging for unactivated olefins, particularly when the substrates lack directing groups or acidic C(sp³)─H bonds. Here, we address this challenge by merging NiH-catalyzed radical relay strategy with a HAT (hydrogen atom transfer) process. In this catalytic system, a nucleophilic alkyl radical is generated from a C(sp³)─H compound in the presence of a HAT promotor, which couples with an alkyl metallic intermediate generated from the olefin substrate with a NiH catalyst to form the C(sp³)─C(sp³) bond. Starting from easily available materials, the reaction not only demonstrates wide functional group compatibility but also provides hydroalkylation products with regiodivergence and excellent enantioselectivity through effective catalyst control under mild conditions.