Synthesis Of Heterocyclic Compounds By Carbonylation Of Formic Acid And Its Derivatives As CO Sources

Carbon-based chemistry is the foundation of life.Carbon plays an irreplaceable role in nature and is an essential element in life.As one of the simplest small molecules,CO gas has been ignored.Since the 1970s,Heck reported the first palladium-catalyzed carbonylation coupling reaction,using CO as a source of carbonyl,which has promoted the research and application of CO gas in carbonylation.CO is a gas that we often use in scientific research.This gas is cheap and has high atomic utilization,especially in industrial applications.However,CO gas itself has great shortcomings:（1）colorless and odorless,leaking is not easy to find;（2）high toxicity and high mortality;（3）high pressure equipment is generally used for industrial applications.To this end,many alternative carbonyl sources have been developed,such as Mo（CO）₆,formamide,and so on.In recent years,our research group has been mainly engaged in the research,development and application of alternative carbonyl sources.Formic acid is an ideal carbonyl source,which has many advantages such as simple preparation,convenient storage and stable properties.In this thesis,formic acid and its derivatives（TFben）are used as carbonyl sources to synthesize heterocyclic compounds by transition metal catalysis,and their transition metal-free catalytic synthesis of important organic heterocyclic compounds.The work described is as follows:（1）For the first time,a one-pot method was used to synthesize a benzofuran compound using formic acid as a carbonyl source.This type of reaction is based on methyl 2-（2-iodophenoxy）acetate,Pd（OAc）₂ as a catalyst,BuPAd₂ as a ligand.The reaction is simple in operation,mild in reaction conditions and uncomplication in separation,which is one of the simple methods for synthesizing benzofuran compounds.（2）For the first time,a novel solid carbonyl source TFben was used in the Pauson-Khand reaction to synthesize a cyclopentenone heterocyclic compound.The PK reaction plays an important role in the synthesis of cyclopentenone compounds.The reaction uses a simple and easily prepared aryl ether compound as a substrate,Co₂（CO）₈ as a catalyst and P（^tBu）₃·HBF₄ as a ligand,which has a very wide range of functional group compatibility and substrate suitability.A good to excellent product of the cyclopentenone structure is obtained.（3）For the first time,a novel solid carbonyl source TFben was used to synthesize a 1,3-oxathiocyclopentan-2-one compound.Developed a practical and simple method for the synthesis of 1,3-oxathiocyclopentan-2-one compounds.Here we do not use transition metals as catalysts,save experimental costs,and use DBU to promote the reaction.And very good separation yields are obtained.