Abstract
Reaction of [PhP(Se)(μ-Se)]2 (Woollins' reagent, WR) with symmetrically disubstituted diynes: five-membered P(Se)Se2C2 heterocycles and bis-heterocycles with two five-membered P(Se)Se2C2 rings connected through a C–C single bond; tBu–CC–CC–tBu reacts differently to afford an unprecedented four-membered P(Se)SeC2 heterocycle with one unreacted triple bond and a fused bis-heterocycle containing two five-membered P(Se)SeC3 rings fused at the middle two carbons of the diyne to give a heterocyclic analogue of