Development of a Unique Heterogeneous Palladium Catalyst for the Suzuki-Miyaura Reaction using (Hetero)aryl Chlorides and Chemoselective Hydrogenation

摘要

Aunique heterogeneous palladium catalyst (7% Pd/WA30) supported on an anion exchange resin, which contains N, N-dimethylaminoalkyl functionalities on the polymer backbone, was developed. 7% Pd/WA30 could smoothly catalyze Suzuki-Miyaura reactions of even less reactive heteroaryl chlorides and heteroarylboronic acids to afford various (hetero) biaryls due to the electron-donating effect of the tert-amines on WA30 to Pd species. It was also applicable as a chemoselective hydrogenation catalyst, showing inactivity for the hydrogenolysis of tert-butyldimethylsilyl (TBS) ethers, alkyl benzyl ethers, and benzyl alcohols. The tert-amines on WA30 acted as moderate catalyst poisons for Pd, resulting in chemoselective hydrogenation. 7% Pd/WA30 was reused for at least five times without any loss of the hydrogenation catalytic activity.