Ｈｙｐｅｒｖａｌｅｎｔ有機よう素化合物を活用する有機合成 けい素，すず化合物との反応

Abstract

Iodosylbenzene activated by the coordination of Lewis acids to the oxygen atom reacts readily with a variety of organosilicon and tin compounds to produce the hypervalent organoiodine (III) species. Allyl- and vinyliodine (III) compounds are highly reactive and act as the species equivalent to allyl and vinyl cations, because iodine (III) at the hypervalent state is a good Ieaving group. Reaction of alkynyliodine (III) compounds with stable enolates of 1, 3-dicarbonyl compounds produces substituted cyclopentenes via the (1, 5) C-H insertion of alkylidene carbene intermediates. 1, 4-Fragmentation of γ-tributylstannyl alcohols using iodosylbenzene, BF3, and DCC gives rise to unsaturated carbonyl compounds. The fragmentation, combined with conjugated addition of Bu3SnLi and reduction or alkylation, offers an efficient procedure for the reductive and alkylative ring opening of cyclic vinyl ketones.