Palladium Catalyzed Decarboxylative Cross-coupling Of Aryl Halides And Oxalate Monoester Salts Under Free Ligand Condition

Transition metal-catalyzed decarboxylative cross-coupling reactions haverecently emerged as a new and important category of organic transformations thatfind versatile applications in the construction of carbon-carbon andcarbon-heteroatom bonds. Heck, Suzuki-Miyaura, Nigishi,, Kumada andSonogashira are the normal main method of the previous. These reaction often usedthe1-5mol%palladium, the complex structure of the organophosphorus compoundas a ligand strict conditions. Organic phosphorus compounds are expensive,sensitive to air and toxic, and its application to become a problem. Thus, itssignificance to Developing free ligand palladium catalyst system for the applicationof the decarboxylative cross-coupling reaction.This paper is a brief summary of the latest research progress inpalladium-catalyzed decarboxylation-coupling reaction recent years, According tothe results of previous. Palladium-catalyzed aryl halides and oxalate monoestersalts generated aryl ester compounds under free ligand conditions of the research beproposed.Palladium-catalyzed decarboxylative cross-coupling reactions of aryl halidesand oxalate monoester salts under free ligand condition were studied. After examiningvarious ratios of reagent, reaction temperature and time, found the optimizedreaction conditions for this transformation. With the optimized conditions, severalAryl acetic acids ester products were prepared.Further broaden the applicability of this reaction, this catalytic system appliedfor aryl halides with2-ethoxy-2-oxoacetate,2-butoxy-2-oxoacetatedecarboxylative cross-coupling reactions. Partial electron withdrawing group arylbromide can also be associated with2-butoxy-2-oxoacetate in this catalyticsystem to get high efficiency yield. In summary, Palladium catalyzed decarboxylativeesterification of aryl halides and oxalate monoester salts under free ligand condition werewide range of applications.