Thiocarbonyl compounds Thioesters

A variety of thiocarbonyl compounds including thioamides, thioureas, and thioesters are converted to their corresponding carbonyl corrqtounds in good yield by simply grinding them with solid Oxone with a mortar and pestle (eq 12)P Thioketones remained unchanged under the reaction conditions. 

Interception of reactive intermediates provides access to an even broader range of products. For example, insertion of CO leads to conjugated lactones and thioe-sters (Scheme 4). A wide variety of sulfur derivatives can be used in these processes producing an array of interesting synthetic intermediates. These organosulfur compounds can be free thiol [164, 167-170, 175, 190, 193, 197, 202, 204], disulfide [160, 165, 183, 207], thiocyanate [179, 182, 186], thioborate [161], thiostannane [196], sulfenamide [180], and thioester [187, 189, 191, 194, 195]. Palladium catalyzed thiocarbonylation, and the development of multicomponent reactions centering on hydrothiolation with free thiols and disulfides has been reviewed extensively [19, 20, 23-26, 167, 227-231]. 

The Pd(OAc)2/PPh3 catalyst is very useful for the thiocarbonylation of a variety of carbon-carbon double-bond compounds such as conjugated dienes [118], allylic alcohols [119], and vinylcyclopropanes [120], as shown in Scheme 35. These reactions proceeds via 7i-allylpalladium complexes as key intermediates. Furthermore, a catalytic system based on Pd(OAc)2/(/ ,/ )-DIOP is found to effect asymmetric thiocarbonylation of prochiral 1,3-dienes to produce good yields of optically enriched p,Y-tmsaturated thioesters [121]. 

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