Generation and typical reactions of thiocarbonyl ylides

In recent years, thiocarbonyl ylides found new application as useful buildi ng blocks in syntheses of sulfur containing heterocycles. They were also sh own to play an important role as key intermediates in two-step [3+2] cycloa ddition reactions. Strategies explored for the generation of thiocarbonyl y lides and their typical reactions including [3+2] cycloadditions, 1,3- and 1,5-electrocyclizations, additions of OH, SH, and NH groups, and rearrangem ents are presented. Reactivities of isolable, push-pull stabilized thiocarb onyl ylides are compared with those proposed as transient species.