Phosphonium-Iodonium Ylides with Heteroatomic Groups in the Synthesis of Annelated P-Containing Heterocycles

The preparation and chemistry of novel sulfonyl- and phosphoryl-derived lambda(3)-iodanes are reported. These compounds with three different heteroatoms attached to a negatively charged C atom represent potentially useful reagents that combine in one molecule the synthetic advantages of a phosphonium ylide and an iodonium salt. Specifically, they can react with a number of acetylenes, leading to hitherto unknown sulfonyl- and phosphoryl-substituted phosphinolines, phosphininothiophenes, and a novel type of annelated P-containing heterocycle-phosphininopyrazole.