Recent Advances and Perspectives in the Chemistry of Sulfenic Acids

Abstract

This review provides a comprehensive survey of the literature on sulfenic acid chemistry from 1990 through June 2006, focusing the attention on salient aspects of their structures and involvement in organic processes. Even if the majority of known sulfenic acids cannot be isolated, some stable ones have been obtained, and their study helped dramatically the comprehension of chemical and physical properties of all sulfenic acids and indirectly of the role that Cys-SOHs play in protein biochemistry. Many papers have been published in the last fifteen years about the sulfenic acid intermediacy in organic chemistry. Once generated, they can be involved in intra-and intermolecular additions to unsaturated molecules. Few examples of sulfenic acid addition to double bonds have been recently described and most of them are intramolecular processes, whereas the addition of enantiopure sulfenic acids onto carbon-carbon triple bonds has been widely exploited in the synthesis of vinyl sulfoxides to be used in many stereoselective transformations. The thermicelimination from sulfinyl precursors is a way to generate sulfenic acids but it has been also used for removing the sulfinyl moiety from organic molecules and forming double bonds with controlled stereochemistry. Some significant applications of extrusion processes are also described in the present review.

A chemical approach for detecting sulfenic acid-modified proteins in living cells

“…18 Electrophilic groups in proteins are rare and thus, this unique property of sulfenic acids can be exploited for their selective detection. To this end, we designed and synthesized a bifunctional chemical probe N-(3-azidopropyl)-3,5-dioxocyclohexanecarboxamide referred to as DAz-1 ( Fig.…”

“…13 Cysteine sulfenic acids are the simplest oxy-acids of organic sulfur and are inherently reactive moieties. 18 Consequently, sulfenic acids are often intermediates en route to more stable oxidation states such as sulfinic (Cys-SO 2 H) and sulfonic acids (Cys-SO 3 H) (Fig. 1a).…”

2,2-Bis(phenylsulfonyl)ethyl sulfides as efficient precursors of sulfenic acids

“…The first step of our project has been the preparation of sulfides 5 by reacting thiols 4 with an almost equimolar amount of strongly electrophilic 1,1-bis(phenylsulfonyl)ethylene (2) 8 in the presence of Triton B as a base (Scheme 2). 9 In order to evaluate the applicability of the method, four thiols have been chosen as models: an aliphatic one [cyclohexanethiol (4a)], an aromatic one [benzenethiol (4b)], phenylmethanethiol (4c), and N-(tert-butoxycarbonyl)-L-cysteine methyl ester (4d).…”

“…In this last case the syn-addition has to obey to more strict steric demands and, before the sulfenic intermediate can succeed in reaching the unsaturation in a proper geometry, it can easily undergo self-condensation to produce thiosulfinates. 2,13 For this reason very few are the examples of efficient syntheses of sulfoxides via sulfenic acid / alkene concerted syn-addition, most of them being intramolecular, because of the easier accessibility of a close double bond to be attached.…”

“…7 Finally, most of the reported syntheses involving sulfenic acid intermediation lead to the formation of vinyl sulfoxides, resulting from sulfenic acid addition on an alkyne, while only few cases involving the addition of 1 to double bonds are reported. 2 This paper intends to demonstrate the central importance of 1,1-bis(phenylsulfonyl)ethylene (2) as a key reagent in the generation of sulfenic acids. The conversion of the sulfinyl precursors takes place even at room temperature (RT), thus limiting the formation of side products to very low yields.…”