Copper(I)–USY as a Ligand-Free and Recyclable Catalyst for Ullmann-Type <i>O</i>-, <i>N</i>-, <i>S</i>-, and <i>C</i>-Arylation Reactions: Scope and Application to Total Synthesis

Abstract

The copper(I)-doped zeolite Cu^I-USY proved to be a versatile, efficient, and recyclable catalyst for various Ullmann-type coupling reactions. Easy to prepare and cheap, this catalytic material enables the arylation and heteroarylation of diverse O-, N-, S-, and C-nucleophiles under ligand-free conditions while exhibiting large functional group compatibility. The facility of this catalyst to promote C-O bond formation was further demonstrated with the total synthesis of 3-methylobovatol, a naturally occurring diaryl ether of biological relevance. From a mechanistic viewpoint, two competitive pathways depending on the nature of the nucleophile and consistent with the obtained results have been proposed.