An η2 transition state for the insertion of M(PR3)2 fragments (M = Pd or Pt) into the phosphorus–carbon bonds of pentacarbonyl(phosphirane)tungsten complexes

Abstract

The reaction of (E)- and (Z)-[W(CO)₅( [graphic omitted]HPh)] complexes with [M(PR₃)₂(C₂H₄)][M = Pd, (PR₃)₂= dppe (Ph₂PCH₂CH₂PPh₂); M = Pt, PR₃= PPh₃] has been studied and the following products [which result from insertion of the M(PR₃)₂ frogment into the phosphirane ring] have been fully characterised by NMR spectroscopy: (2R*,3S*,4S*)-(±)-, (2R*,3S*,4R*)-(±)- and (2R*,3S*,4R*)-(±)-[(dppe) Pd(CHPhCHPhPPh)W(CO)₅]; (2S*,3S*,4S*)-(±)-, (2S*3R*4R*)-(±)- and (2S*,3S*,4R*)-(±)-[(Ph₃P)₂Pt(CHPhCHPhPPh)W(CO)₅]; and trans-(2S*,3S*,4R*)-(±)-[(Ph₃P)(OC)Pt-(CHPhCHPhPPh)W(CO)₅]. The crystal and molecular structures of (Z)-[W(CO)₅([graphic omitted]HPh)], (2R*,3S*,4R*)-(±)- and (R*,3S*,4S*)-(±)-[(dppe)Pd(CHPhCHPhPPh)W(CO)₅] have been determined. The configurations of the products are interpreted in terms of a transition state in which a P–C bond is η²-co-ordinated to M(PR₃)₂ fragment.