The Construction Of Methyl Sulfones Via Green Sulfur Dioxide Source

Methyl sulfones,as a vital part in the family of sulfones,exist extensively in pharmaceuticals,agrochemical molecules and so on.Hence it’s crucial to develop efficient green approaches for their construction.The most traditional method for the construction of methyl sulfones is that oxidizing the corresponding sulfides with strong oxidants,which will lead to the limited substrate scope,poor atomic economy and step economy,environmentally unfriendly etc.Furthermore,thiol,a high toxicity reagent with pungent smell,is used for the construction of sulfides.Iodomethane which is a high toxic reagent is still widely used as methyl source.These years,sulfur dioxide source which is a significant building block for sulfones has drawn much attention.It has obvious advantages than traditional ones,such as avoided the use of strong oxidants,reagents with corrosivity and toxicity.We choose the eco-friendly sodium metabisulfite as the sulfur dioxide source,dimethyl carbonate which is more and more recognized and accepted as a kind of novel green solvents recent years as methyl source.We achieved the construction of methyl sulfones via transition-metal catalyzed three-component cross-coupling strategy with simple operation.We have avoided poor atomic economy and step economy,and environmentally unfriendly in traditional methods.Meanwhile,multifarious functional groups could be compatible in this reaction indicated that this method was of well practicality,which has solved the limited substrate scope in traditional ways.Plenty of pharmaceutical molecules could be late-staged quickly and some methyl sulfone drugs could be synthesized through our method which has a significant influence on promoting the development of drug discovery.