Palladium/Copper-Catalyzed Oxidative C-H Alkenylation/N-Dealkylative Carbonylation of Tertiary Anilines

摘要

Anilines are valuable commodity chemicals and useful synthetic building blocks for agrochemicals, active pharmaceutical ingredients, and process chemicals. Although anilines have been widely utilized in chemical synthesis, the ortho-selective C—H bond functionalization of anilines still remains an outstanding challenge. During the past decade, Pd-catalyzed aromatic C—H functionalization to form C—C and C—X bonds has been intensively investigated. However, to our best knowledge, the oxidative alkenylation of anilines through the ortho-selective direct C—H bond functionalization have never been achieved. On the other hand, activation of the C—N bond has become a hot topic in organic synthesis recently, in which most efforts were focused on the amination transformation. As a typical example of tertiary amines, tertiary anilines have also been utilized in C—N bond cleavage transformations. However, the utilization of tertiary anilines as nitrogen nucleophiles with alkyl as leaving group in oxidative carbonylation has remained undeveloped. Herein, we present the first palladium/copper-catalyzed oxidative C— H alkenylation/N-dealkylative carbonylation of tertiary anilines towards the synthesis of 3-methyleneindolin-2-ones derivatives (Scheme 1).