Unexpected four- and eight-membered organo P–Se heterocycles

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 pentalene, [3.3.0]octa-1-6-diene.