Rapid and Efficient Deoxygenation of Sulfoxides with NbCl5/NaI System

摘要

The deoxygenation of sulfoxides to the corresponding sulfides is an important reaction that has found utility in organic synthesis and in biochemical reactions. Accordingly, a good number of methods have been developed for the reduction of sulfoxides to the corresponding sulfides. However, they often suffer from serious disadvantages, such as functional group incompatibility, difficult work-up procedures, harsh reaction conditions, or not readily available reagents. Further some of these methods are associated with limitations regarding low yields and prolonged reaction times. Therefore, the search for a new and efficient method for the deoxygenation of sulfoxides is still a worthwhile goal. Particularly much effort has been devoted to the development of milder conditions where the presence of various sensitive and reducible functional groups can be tolerated. The use of low valent oxophilic d-block metals (Zr, Ti, W, Mo) have become important in deoxygenation of various types of organic substrates.In this regard, deoxy-genations of epoxides, sulfoxides and amine N-oxides are readily performed with low valent niobium generated by reacting NbCl5 with Zn. We envisaged that NbCl5/NaI system can be an efficient reducing agent for the reduction of sulfoxides to sulfides.