Cyanation of aryl halides and Suzuki-Miyaura coupling reaction using palladium nanoparticles anchored on developed biodegradable microbeads

This work reports i) green synthesis of palladium nanoparticles (Pd NPs) on the developed biodegradable microbeads as stabilizers, featuring chitosan, agarose and beta-cyclodextrin, ii) investigation of the catalytic role of the Pd NPs prepared in the Suzuki-Miyaura and iii) cyanation reactions. Pd NPs@microcapsules (CAP) convert a series of aryl halides to biphenyl compounds with yields ranging from 79 to 98%. Pd NPs@CAP is highly active in the cyanation of different aryl bromides and iodides using K₄[Fe(CN)₆] and is used to prepare benzonitriles with a yield of up to 97%. More importantly, Pd NPs@CAP is easily recovered from the reaction mixture and successfully reused seven consecutive times in the Suzuki-Miyaura and cyanation reactions. This significant features of Pd NPs@CAP are i) ease of purification of desired biaryls and benzonitriles and ii) production of no by-products in both catalytic reactions.