Oxygen-promoted coupling of arylboronic acids with olefins catalyzed by [CA]2[PdX4] complexes without a base
作者:E. Silarska、A.M. Trzeciak
DOI:10.1016/j.molcata.2015.07.003
日期:2015.11
An efficient method was developed for the oxidative Heck reaction between arylboronic acids and olefins catalyzed by anionic palladium complexes of the type [CA](x)[PdCl4] (x = 1,2) and [CA](2)[Pd2Cl6] (CA= imidazolium or pyridinium cation). Molecular oxygen was employed as an environmentally benign oxidant to regenerate Pd(II) species during the reaction. The elaborated protocol could be applied to the coupling of different arylboronic acids with both electron-rich and electron-poor olefins. The catalyst system was further employed for the one-pot oxidative Heck reaction followed by the Heck coupling to build conjugated compounds in good yield.Mass spectrometry (ESI-MS) and UV-vis spectroscopy was used to identify palladium-containing complexes in the reactions. A plausible reaction mechanism of the oxidative Heck reaction was proposed. (C) 2015 Elsevier B.V. All rights reserved.
Triaryl phosphine-functionalized N-heterocyclic carbene ligands for Heck reaction
作者:Ai-E Wang、Jian-Hua Xie、Li-Xin Wang、Qi-Lin Zhou
DOI:10.1016/j.tet.2004.10.049
日期:2005.1
A new type of triaryl phosphine-functionalized imidazolium salts 6 were prepared. Their palladium complexes, generated in situ, were successfully applied in the palladium-catalyzed Heck reaction. Using 1 mol% of Pd(dba)(2) and 10 mol% 6c in the presence of 2 equiv of K2CO3 in DMAc has proven to be highly efficient for the coupling of a wide array of aryl bromides and iodides with acrylates in excellent yield. The coupling of 4-bromotoluene with various styrene derivatives catalyzed by Pd/6c complex also gave good results. (C) 2004 Elsevier Ltd. All rights reserved.