Light For The Next Non-precious Metal-catalyzed Carbonylation Reaction

Carbonylation is one of the most important organic synthesis which usually takes place at high temperatures and high pressure with precious catalysts. In recent years, more and more attention has been paid to the photo-promoted carbonylation under ambient conditions.In this paper, the carbonylation has been studied of olefins in different solvent systems. It is found that carbonylation of olefins with carbon monoxide can take place in CH3OH-THF, CH3OH-dioxane and CH3OH-DMF under the catalysis of cobalt complexes, where double bonds shift has been found. The effect of different cobalt catalysts on carbonylation has been researched and it is found that different ligands have different influence on efficiency of catalysts. Further research shows that DMF can be decomposed into CO and thus can be used as a convenient CO source. Carbonylation of olefins can be completed in CH3OH-DMF without adding additional carbon monoxide by catalysis of cobalt complexes under irradiation. If the reaction was carried out under CO in CH3OH-DMF, both CO and DMF are the carbon source. If the reaction takes place under CO2, the yields can be improved greatly, and DMF is the only carbon source, which has been proved by isotope experiment of H13CON(CH3)2.On the basis of homogeneous carbonylation, nano cobalt is synthesized by reduction in aqueous solutions, and the carbonylation of olefins in CH3OH-CH3COCH3 is carried out under the catalysis of nano cobalt.The research has been done for the carbonylations of benzyl halogen and its derivatives in CH3OH-CH3COCH3 under CO and in CH3OH-DMF under CO2. Usually benzyl halogen and its derivatives do not show high activities in carbonylations and side reactions are easier to take place by irradiation both in CH3OH-CH3COCH3 under CO and in CH3OH-DMF under CO2. The interesting results of carbonylations of benzyl halogen and its derivatives are obtained that benzenes with groups of donating electrons are beneficial to carbonylation and benzenes with groups of withdrawing electrons are unfavorable to or even no carbonylation in CH3OH-CH3COCH3. In the presence of CO2, carbonylation of benzyl halogen with HCON(CH3)2 show higher activities in CH3OH-DMF than in CH3OH-CH3COCH3. It is found that benzenes with groups of donating electrons show less effect on carbonylation, and no carbonylation of benzenes with groups of withdrawing electrons take place inCH3OH-DMF.