Rhodium-Catalyzed Carbonylation Of Butenolides

In the past few decades,transition metal catalysis has attracted much attention in the field of organic synthesis,especially the use of carbonylation reaction to construct new c-c bonds,which provides an efficient and convenient synthesis method for the construction of carbonyl compounds.Carbonylation can be done not only in the laboratory,but also in industrial production.For example,in the 1930 s,carbon monoxide was used as a source of carbonyl for hydroformylation in industrial production.In most carbonylation reactions,carbon monoxide is used as the source of carbonyl group,on the one hand,it has high atomic utilization rate,on the other hand,it is relatively cheap and easy to obtain.As an important unit,butenolide appears in a variety of bioactive natural products or drugs,such as triptolide,vitamin C,and so on.Therefore,its synthesis has attracted much attention.In the past period of time,a lot of methods to synthesis of butenolide have been established,like transition metal catalysis molecular internal ring of butyric acid,acid and tertiary alcohol ketone intermolecular cyclization,but there are often need complex,harsh reaction conditions,and low yield.So,in order to achieve the functionalization of butenolide and its derivatives efficiently build,urgent need to develop some new synthetic methods.In this paper,firstly,the author summarized the relevant reactions of carbonylation,and then elaborated some synthesis methods of butenolide in recent years.Finally,based on the research and interest of our research group on carbonylation,it was reported that rhodium-catalyzed carbonylation was used to synthesize butenolide derivatives.In the reaction,carbon monoxide was used as the carbonyl source and rhodium as the metal catalyst.Asymmetric acetylene was reacted with aryl boric acid,two carbon monoxide were inserted,and butylactone were synthesized efficiently in high area selectivity.