Copper-Free Heck–Cassar–Sonogashira and Suzuki–Miyaura Reactions of Aryl Chlorides: A Sustainable Approach
Chiara Palladino, Tommaso Fantoni, Lucia Ferrazzano, Alessandra Tolomelli, Walter Cabri
Abstract
High Resolution Image Download MS PowerPoint Slide Sustainable and efficient aryl halides with copper-free Heck–Cassar–Sonogashira (HCS) and Suzuki–Miyaura (SM) cross-coupling reactions were described. Independently from the aryl chloride substituents, the green protocol based on N -hydroxyethylpyrrolidone (HEP)/water as solvents and sodium 2′-dicyclohexylphosphino-2,6-dimethoxy-1,1′-biphenyl-3-sulfonate (sSPhos) as ligand afforded the target products with a high turnover number (TON), high reaction mass efficiency (RME), and low process mass intensity (PMI). The best results have been obtained with TMG and Cs 2 CO 3 as the base for the HCS and Cs 2 CO 3 and K 2 CO 3 for the SM coupling. The PMI and RME achieved are among the best in the field and allowed us to simplify purification processes that are critical for industrial applications.