Research On Construction Of Sulfonyl Functionalization Reaction Based On Sulfur Dioxide Radical Process

Sulfur dioxide,widely found in nature,is an important form of transformation of S element.Sulfur dioxide was discovered by ancient humans during bonfires in ancient times.Sulfur dioxide,however,is also a major component of atmospheric pollution.The development of modern industry has led to a great deal of sulfur dioxide,which turns into the main component of acid rain in the air.Massive erosion has been caused to trees,buildings,and ground surfaces.Therefore,the governance of sulfur dioxide is an important part of environmental governance.The application of sulfur dioxide to organic synthesis is one of the ways of governance of sulfur dioxide.Sulfonyl group is a kind of structure widely found in various compounds.It is a common synthetic block and also a bioactive structure.Therefore,the construction method of sulfonyl group has always been a research hotspot.Sulfur dioxide inserting is one of the most effective ways of sulfonyl group constraction.In many previous studies,many methods have been developed to react with gaseous sulfur dioxide.Due to the special nature of gaseous sulfur dioxide,which is difficult to control and is not suitable for use in laboratories,it has greatly restricted its application in organic synthesis.In recent years,sulfur dioxide carrier reagents have gradually become effective methods for the construction of sulfonyl groups.Compared to the previous methods,sulfur dioxide can be directly introduced into the sulfonyl group without the need to synthesize precursor materials in advance.The synthetic efficiency and substrate range of sulfonyl group have been greatly extended.In this paper,the introduction of sulfonyl groups into small organic molecules is focused on the synthesis of solid sulfur dioxide carrier as a sulfonyl source by free radical cascade synthesis.Mainly from the following Two aspects of work were inclouded:1.Transition-Metal-Free Oxidative Reaction of Hydrazines and Potassium Metabisulfite for Preparation of SulfonohydrazidesA transition-metal-free oxidative coupling reaction for the synthesis of sulfonohydrazides from two types of hydrazines and potassium metabisulfite under air has been developed.This highly selective reaction used one arylhydrazine as an aryl coupling partner and potassium metabisulfite as a sulfur dioxide precursor,which provides a new and green strategy to sulfonohydrazides.2.Enantioselective Synthesis of sulfonylation Lactones via Copper Catalyzed Radical Oxyfunctionalization of Alkenes with Aryldiazonium Tetrafluoroborates and DABCO·(SO2)2A method based on sulfur dioxide carrier DABSO was developed to construct asymmetric lactone containing sulfonyl through the cyclization reaction of diazonium salts,unsaturated olefins carboxylic acid by radical process.This method is the first time to apply DABSO to asymmetric catalysis.This method provides a direct introduction of sulfonyl functional groups in asymmetric lactone.