Rhodium(II) Catalyzed Cyclization of Diazo Thiocarbonyl Compounds for Heterocycloic Synthesis
摘要:
The mesoionic thioisomunchnone system was prepared from the rhodium(II) acetate catalyzed cyclization of a diazothioamide and was found to undergo smooth 1,3-dipolar cycloaddition with N-phenylmaleimide. In contrast to this system, the rhodium(II) reaction of an alpha-diazo-beta-oxo ester containing a thiocarbonyl group produced a cyclic thiocarbonyl ylide which extruded sulfur from a transient episulfide intermediate.