Construction Of Sulfonic Acid Using Inorganic Sulfur Salt

Sulfonic derivatives are pervasively found in pharmaceuticals,materials,additives,surfactant,dyes and some of the nature product with important bioactive,and they are important classes of functional molecules.The introduction of sulfonic groups into molecules may bring some advantages to the rationalize properties of functional molecules,which are of great significance for drug modification,material improvement and so on.The traditional sulfonation reaction is the main way to introduce the sulfonic group,which mainly uses high-risk,high-toxic raw materials as sulfonating reagent,such as fuming sulfuric acid,sulfur trioxide or sulfur dioxide.At the same time,this process maybe take places under high reaction temperature,which is not only difficult to operate,but also unfriendly to the environment.Based on this background,i developed a green,efficient,cheap and simple sulfonation approach.I used the strategy of sulfur atom transfer by employing non-toxic,odorless thiourea dioxide as sulfonating reagent,aryl iodide as precursor,air as oxidant and a little amount of metal palladium as catalyst to construct a series of diversity aromatic sulfonic acid compounds under heating conditions.Meanwhile,alkyl sulfonic acid compounds were constructed using alkyl bromide under the no metal catalyst.In addition,we also achieved postmodification of some complex molecules with important physiologically activity.On the basis of these control experimental,we also studied the reaction mechanism,and proposed the possible pathway of the reaction.I used cheap and stable sodium dithionite as sulfur source,the high sterically hindered alkyl carboxylic acid active by redox-active esters as percursor and oxygen as oxidant to establish a reaction model for metal-free catalytic decarboxylation sulfonation under heating conditions,and simply explored the process of this reaction.In this type of sulfonation reaction,i used mild conditions,and avoided use of high-risk vulcanization reagents,which conforms to the concept of green chemistry.