The reaction of metal carbonyls with phosphorus methylene and allylidene ylides: Allylidene(triphenylphosphorane)tetracarbonylmolybdenum and -tungsten a non-classical allylic system

Abstract

The carbonyls Mo(CO) 6, W(CO) 6, Fe(CO) 5 react with methylenetriphenylphosphorane in tetrahydrofuran to give tris(tetrahydrofuranate) of 1 1 metal carbonyl-phosphorus ylide adducts, which are thought to be oxonium salts. Allylidene-triphenylphosphorane reacts with Mo(CO) 6 or W(CO) 6 in boiling tetrahydrofuran to yield (CO) 4M[(C 6H 5) 3PHCHCH 2]. Preliminary X-ray analysis of the molybdenum complex has revealed the presence of a non-classical allylic system on the metal. The complex reacts with triphenylphosphine with displacement of one carbonyl group, to give (CO) 3Mo[P(C 6H 5) 3][(C 6H 5) 3PHCHCH 2].