Nickel/Brønsted acid dual-catalyzed regioselective C–H bond allylation of phenols with 1,3-dienes†
Abstract
Selective alkylation of phenols is an efficient strategy for the preparation of phenol derivatives. However, owing to the ambident nucleophilic reactivity of these substrates, chemoselectivity is a predominant challenge in these reactions. Herein, a nickel/Brønsted acid dual-catalyzed regioselective allylation of phenols with 1,3-dienes has been established. In this dual-catalytic pathway, ortho-selective C–H bond allylation of the phenol ring and Markovnikov-selective 1,2-addition of 1,3-dienes were favored. This methodology is characterized by its inexpensive catalyst, broad substrate scope, and good chemo- and regioselectivity.