An Efficient Protocol for a Pd(OAc)2-Catalyzed Ligand-Free Suzuki Reaction in Toluene

Abstract

An efficient protocol for a Pd(OAc) 2 -catalyzed ligand-free Suzuki reaction of aryl bromides with arylboronic acids in the presence of K 3 PO 4 ·7H 2 O in toluene under mild and aerobic conditions afforded cross-coupling products in good to excellent yields. Under the optimized reaction conditions (i.e., 0.5 mmol ArBr, 0.75 mmol ArB(OH) 2 , 1 mol% Pd(OAc) 2 , 1.0 mmol K 3 PO 4 ·7H 2 O, 2 ml toluene), the Suzuki reaction between 4-nitrobromobenzene and phenylboronic acid afforded a 99% isolated yield in 5 min at 75 °C and a TOF of up to 1 188 h −1 . ：报道了一种甲苯中醋酸钯催化无配体的 Suzuki 反应体系. 以 K 3 PO 4 ·7H 2 O 为碱, 在该体系中可高效进行芳基溴代物和芳基硼酸的 Suzuki 反应, 且具有反应条件温和、无需惰性气体保护等特点. 在 n (ArBr) = 0.5 mmol, n (ArB(OH) 2 ) = 0.75 mmol, x (Pd(OAc) 2 ) = 1 mol%, n (K 3 PO 4 ·7H 2 O) = 1.0 mmol, v (甲苯) = 2 ml 的优化条件下, 4-溴硝基苯和苯硼酸在 75 °C 反应 5 min, 分离收率即达 99%, TOF 高达 1 188 h $ - $1 . We developed a simple and efficient protocol for a Pd(OAc) 2 -catalyzed aerobic ligand-free Suzuki reaction of aryl bromides with arylboronic acids in the presence of K 3 PO 4 ·7H 2 O in toluene.