Silyl-mediated and oxidative synthesis of sulfines

In this thesis new synthetic methods for sulfine preparation are described. Chapter 1 is an introduction into the sulfine chemistry with the focus on recent developments. In chapter 2 the oxidation of thiocarbonyl compounds is carried out using dimethyl dioxirane. Due to the simple work-up of removing the side-product acetone by evaporation, this method improves the possibilities of isolation of labile sulfines. Chapter 3 deals with the dehydrosiloxylation as a new method for the formation of sulfines by a base induced elimination of a silanolate anion from a silyl sulfinate ester. These silyl sulfinate esters are readily prepared by a reaction of silyl ketene acetals with sulfur dioxide. Two non base induced synthetic methods for sulfine synthesis are described in chapter 4: the desilylsiloxylation and the desilylchlorination. These methods respectively eliminate bi(trimethylsilyl) ether and trimethylsilyl chloride from alpha-silyl silyl sulfinate esters and alpha-silyl sulfinyl chlorides. These starting materials are prepared by a reaction of alpha-silyl ketene silyl acetals with respectively sulfur dioxide and thionyl chloride. Chapter 5 describes the synthesis and reactions of a new class of sulfines namely the epoxy sulfines. The structure of one of the epoxy sulfines was verified by X-ray analysis. The final chapter deals with the preliminary results of nucleophilic addition of alkynes to sulfines resulting in alkynyl sulfoxides