Microwave Assisted Solvent Free Catalytic Amino-Carbonylation of Aryl Bromide by Using μ-Dichloro-bis(benzylidene aniline)palladium(II) Complex as Catalyst

Abstract

Solvent-free aminocarbonylation (Heck carbonylation) of aryl halide, catalyzed by μ-dichloro-bis(benzylidene aniline)palladium(II) complex yields dimethyl benzamide and their substitutes, has several useful industrial applications. In present work, dimethylformamide (DMF) serves as an effective in situ supplier of dimethyl amine and carbon monoxide. Bromobenzene along with more electron-rich aryl bromide generally undergo these reactions very smoothly, but the yield of respective products is less. To increase the yields of aryl amide, it is needed to be add amines from the external sources to the reaction mixture. Imidazole and aniline were used as good reaction partners, or amines, in this experiment. For obtaining the best results, several reactions were conducted in the presence of base i.e. potassium tert-butoxide. Potassium tert-butoxide was responsible for the better decomposition of DMF and imidazole as an additive. The carbonylation reactions described here depend on the efficiency of in situ generation of carbon monoxide, which can be a suitable unconventional route to traditional carbonylation procedures for small-scale operation when a quick reaction time is sought where direct use of CO gas is not possible.