Heck–Matsuda Reactions Catalyzed by a Hydroxyalkyl‐Functionalized NHC and Palladium Acetate

Abstract

AbstractThe functionalized NHC obtained from salt 2 is a good ligand for palladium in the Heck–Matsuda reaction of arenediazonium salts and different alkenes. The reaction is performed with low catalyst loading (0.5–1 mol‐% of Pd) and in the absence of a base for acrylates. The protocol is also useful for the preparation of cinnamide derivatives. Compound U‐77863 has been prepared successfully in good isolated yield. Cyclohexene was found to be an appropriate substrate for the reaction, giving the corresponding 1‐arylcyclohexene as a single regioisomer under the studied reaction conditions. The optimal parameters of the reaction were studied by employing a design of experiments approach. Thus, the use of a small set of reactions allows the trends of the different factors to be studied. This study revealed that the best catalytic system is formed by combination of Pd(OAc)2 and salt 2 in a 1:2 ratio. This catalytic system produces better results without the use of a base.