Very Fast Suzuki–Miyaura Reaction Catalyzed by Pd(OAc)2 under Aerobic Conditions at Room Temperature in EGME/H2O

Abstract The results of a ligand‐free Pd(OAc) 2 ‐catalyzed Suzuki–Miyaura C–C coupling performed at room temperature under aerobic conditions are presented. It was found that the use of an ethylene glycol monomethyl ether/H 2 O mixture as the solvent resulted in very rapid reactions of aryl bromides with arylboronic acids. As a matter of fact, under optimized conditions, some substrates were converted quantitatively in less than 1 min with exceptionally high TOF values. For example, the reaction between 4‐methoxyphenylboronic acid and bromobenzene afforded 4‐methoxybiphenyl in 30 s with TOF = 180000 h –1 . Furthermore, the reaction tolerates a wide range of functional groups and can be successfully applied to heteroaryl bromides such as 2‐bromopyridine and 5‐bromopyrimidine. Interestingly, also an activated aryl chloride such as 1‐chloro‐4‐nitrobenzene reacted quantitatively with phenylboronic acid at 373 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)