Chloroesterification Of Alkenes With Tert?butyl Hypochlorite And Carboxylic Acids

??chloroesters have been widely used in the filed of pharmaceutical,dye and pesticide.From the perspective of economy,the direct chloroesterification of alkenes was believed to be the most effective method for the preparation of??chloroesters.Various chlorine sources were developed for this transformation,for example,the chloroesterificati on using N?chlorosuccinimide?NCS?or 1,3?dichloro?5,5?Dimethylhydantoin?DCDMH?as the chlorine sourceand the chloroesterification of ethylene oxide by using 3,3?dimethylsuccinyl chloride as the chlorine source.However,the above chlorination reagents are difficult to prepare and the reaction conditions are relatively harsh,such as excessive acid is needed.It is necessary to develop a new synthesis method to realize the chloroesterification of alkenes.In this paper,the three-component coupling reaction of alkenes with tert?butyl hypochlorite and carboxylic acid was studied,and a new method for the synthesis of??chloroesters was developed.The effects of solvent,chlorine source and substrate amount on the reaction were systematically investigated.The optimal reaction conditions were determined as follows:Alkenes?3.0 equiv?,Tert?butyl hypochlorite?3.0 equiv?,DCM?3 ml?.The reaction was carried out at 25?for 24 hours.Under the optimal reaction conditions,the coupling reactions of various carboxylic acid and alkene substrates were investigated,and the yield was between 59?97%.The results showed that the electronic properties of substituents had little effect on the reaction.Not only aliphatic and aromatic carboxylic acids,but also alkenes had high reactivity.By exploring the mechanism of the reaction,it is speculated that the reaction maybe go through the process of free radical oxidation-reduction and electrophilic addition.The structure of the products obtained was characterized by ¹H NMR,¹³C NMR,IR and HRMS.