Expanding the Horizons of Suzuki Reactions: Pd-PEPPSI–Mediated Traditional and Decarbonylative Couplings With Diverse Assure Analogues

Abstract

We have developed a highly efficient, ligand-free Suzuki–Miyaura cross-coupling protocol employing our lab-prepared air and moisture-stable Pd-PEPPSI catalysts. The reaction of ethyl 2-{4-[(6-chloroquinoxalin-2-yl)oxy]phenoxy}propionate (Assure) with various boronic acids afforded both traditional and decarbonylative coupling products in high yields. The catalyst's steric influence was assessed computationally using %Vbur calculations. The decarbonylative coupling pathway proved more efficient than the traditional Suzuki–Miyaura coupling under these conditions. Additionally, regioselectivity studies have been conducted on a variety of Assure analogues. This method excels in efficiency, requiring minimal catalyst, moderate temperatures, and rapid reaction completion.