Some Sulfenylation And Sulfonylation Reactions Of Sulfonyl Hydrazides And N-Hydroxy Sulfonamides

Sulfone and thioether compounds are present in a large number of natural products and pharmaceutical molecules,and are also widely used as synthetic intermediates.Recently,sulfonyl hydrazides as sulfenylating agents are much more amenable to handling because,in general,they are readily accessible solids,free of unpleasant odor,and compatible with moisture.Sulfonyl hydrazide can react with various organic compounds to obtain sulfides by forming S-C bonds.However,in particular,the reaction types of N-hydroxy sulfonamides as sulfonyl sources are less than that of sulfonyl hydrazides.In addition,N-hydroxy sulfonamides as sulfenylating agents have not been reported.In order to expand the application of sulfonyl hydrazines as sulfenylating agents in organic reactions,and the development of N-hydroxy sulfonamides as an unprecedented new sulfenylating agents and as sulfonyl sources in cyclization reaction,the following four works were discussed in this dissertation.In this dissertation,an unprecedented radical tandem sulfenylation/cyclization reaction of sulfonyl hydrazides and N-arylacrylamides has been developed in the presence of iodide for the selective synthesis of 3-(sulfenylmethyl)oxindoles and 3-sulfenyl-3,4-dihydroquinolin-2(1H)-ones.Preliminary mechanistic studies showed that sulfonyl hydrazides decomposed completely at an early stage to thiosulfonates and disulfides,both of which underwent tandem radical sulfenylation/cyclization with N-arylacrylamides at a late stage.The sulfenylation of the remote C5-H of oxindoles with sulfonyl hydrazides as unique sulfur electrophiles has been developed under the presence of iodine for selective synthesis of structurally diverse oxindole and 3,4-dihydroquinolin-2(1H)-one thioethers in moderate to excellent yields with extremely high regioselectivity,wherein water and molecular nitrogen are expected to be generated as environmentally benign by-products.In this dissertation,a conceptually new synthetic application of N-hydroxy sulfonamides to the sulfenylation of aromatic compounds has established through cleavage of S=O and S-N bonds.In the presence of 10 mol%iodine and 30 mol%N-hydroxysuccinimide,a range of N-hydroxy sulfonamides smoothly participated in sulfenylation with indoles,7-azaindole,N-methyl pyrrole,and 2-naphthol to afford structurally diverse thioethers in moderate to excellent yields with high regioselectivity.Preliminary mechanistic studies show that N-hydroxy sulfonamides firstly decompose to sulfinic acids and then participate in sulfenylation with aromatic compounds.This study paves the way for the use of N-hydroxy sulfonamides as sulfenylating agents in chemical synthesis.Next,an unprecedented radical tandem sulfonylation/cyclization reaction of N-arylacrylamides or N-methacryloylbenzamides and N-hydroxy sulfonamides as new sulfonyl sources has been developed in the presence of silver nitrate and potassium persulfate for the selective synthesis of structure diversified oxindoles and isoquinoline-1,3(2H,4H)-diones in moderate to good yields with high regioselectivity.