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

摘要

Reaction of [PhP(Se)(μ-Se)]_2 (Woollins' reagent, WR) with symmetrically disubstituted diynes: five-membered P(Se)Se_2C_2 heterocycles and bis-heterocycles with two five-membered P(Se)Se_2C_2 rings connected through a C-C single bond; ~tBu-C ≡ C-C ≡ C-~tBu reacts differently to afford an unprecedented four-membered P(Se)SeC_2 heterocycle with one unreacted triple bond and a fused bis-heterocycle containing two five-membered P(Se)SeC_3 rings fused at the middle two carbons of the diyne to give a heterocyclic analogue of pentalene, [3.3.0]octa-1-6-diene.