Phosphinidene reactivity toward unsaturated phosphorus heterocycles

The transient electrophilic phosphinidene complex PhPW(CO)(5) reacts in the presence of CuCl at room temperature with phospholene 2 and phospholes 4a- c to give the corresponding W(CO)(5) complexed products 3 and 5a-c. The int ermediate phosphoranylidene phosphine complexes, formed, from the addition of PhPW(CO)(5) to the phosphorus atom of the substrates, are characterized by NMR spectroscopy and by a single crystal X-ray structure determination f or the one generated from phospholene 2. This intermediate 8 is a CuCl-comp lexed dimer, which speculatively results from dissociating the phosphole-Cu Cl tetramer on insertion of PhPW(CO)(5) into the P-Cu bonds. Reacting PhPW( CO)(5) with phospholene 2 at 110 degreesC in the absence of CuCl gives besi des the W(CO)(5)-complexed phospholene 3 also a bisphospholene-W(CO)(4) com plex 13. The formation of 13 is attributed to a ligand exchange reaction in the intermediate phosphinidene-phospholene adduct. (C) 2001 Elsevier Scien ce B.V. All rights reserved.