PAMAM dendrimer-palladium complex catalyzed synthesis of five-, six- or seven membered ring lactones and lactams by cyclocarbonylation methodology

Abstract

Palladium complexes immobilized onto generations 0–3 PAMAM dendrimers supported on silica, in the presence of 1,4-bis(diphenylphosphino)butane, were used as catalysts for the cyclocarbonylation of 2-allylphenols, 2-allylaniline, 2-vinylphenol and 2-vinylaniline affording five-, six- or seven membered ring lactones and lactams. Good conversions were realized using the catalytic system, and the catalyst was recycled 3–5 times. The influence of the spacer chain was investigated, as well as the solvent and the CO/H 2 ratio, on the selectivity and the recyclability of the cyclocarbonylation reactions.