Oxidation-Reduction Reactions of Organic Sulfur Compounds

摘要

Study of the mechanisms of various oxidation-reduction reactions involving organic sulfur compounds has led to the discovery of several mechanistic principles of general importance to organic sulfur chemistry. These are: (1) the scission of a variety of sulfur-sulfur bonds is subject to concomitant electrophilic and nucleophilic catalysis, with the result that in acid solution the rate of many S-S bond scissions can be strikingly accelerated by the addition of very small amounts of weak nucleophiles; (2) the ease of homolytic dissociation of various sulfur-sulfur bonds varies dramatically with the oxidation state of the sulfur atoms participating in the sulfur-sulfur bond, there being something like a 10 to the 9th power fold difference in the rate of dissociation of the S-S bond in a disulfide and that in a sulfinyl sulfone; (3) a scale of relative nucleophilicity for attack of various nucleophiles on sulfinyl sulfur was obtained and the results compared with substitutions at sp3-carbon and divalent oxygen. (Author)