Ring opening of three-membered heterocycles by terminal phosphinidene complexes

Article abstract of DOI:10.1021/om00153a027

(Phenylphosphinidene)pentacarbonyltungsten as produced by thermal decomposition of the appropriate 7-phosphanorbornadiene complex reacts with phenyloxirane to give (2,4-diphenyl-1,3,2-dioxaphospholane)-and (1,2-diphenylphosphirane)pentacarbonyltungsten complexes. Their formation is explained by the insertion of the phosphinidene into the oxirane ring giving a transient 1,2-oxaphosphetane, which then undergoes a [2 + 2] cycloreversion. With 1-tert-butyl-2-phenylaziridine, the same insertion takes place but the isomeric 1,2-azaphosphetane complexes thus formed are thermally stable. With trans-2,3-diphenylthiirane, decomposition into stilbene and formation of phosphirane complexes take place in lieu of the expected insertion.