Study On Intramolecular Cycloaddition Of Organophosphorus Compounds With Alkyne

Diphenylphosphino-substituted enynes with the Z stereochemistry and their benzo analogues react with an excess of lithium at room temperature in THF to give the corresponding phospholides or benzophospholides with cleavage of the two P-Ph bonds. This chemistry is used to synthesize an original phosphorus-silicon heterotetracene whose structure is established by X-ray crystal analysis. X=O,SPhosphorus ylides play an important role in organic and organometallic chemistry. Here, we report an intramolecular cycloaddition of phosphorus ylides with unactived alkyne, which provide a new method to synthesize cyclic phosphorus ylieds.