A Copper- and Amine-Free Sonogashira Reaction of Aryl Halides Catalyzed by 1,3,5-Triaza-7-phosphaadamantane Palladium Systems

Abstract

The monomeric complex [Pd(dmba)Cl(PTA)] [dmba = N,C-chelating 2-(dimethylaminomethyl)phenyl; PTA = 1,3,5-triaza-7-phosphaadamantane] has been obtained and its crystal structure has been established by X-ray diffraction. Conditions for an efficient copper- and amine-free catalyzed Sonogashira reaction of aryl bromides and chlorides with terminal alkynes by [Pd(dmba)Cl(PTA)] and Pd(OAc)2/PTA have been developed. It is worthwhile noting that a relatively low palladium catalyst loading has been employed.