Evidence for Iron-Catalyzed α-Phosphinidene Elimination with Phenylphosphine.

The ubiquitous half-sandwich iron complex [CpFe(CO)2 Me] (Cp=η5 -C5 H5 ) appears to be a catalyst for α-phosphinidene elimination from primary phosphines. Dehydrocoupling reactions provided initial insight into this unusual reaction mechanism, and trapping reactions with organic substrates gave products consistent with an α elimination mechanism, including a rare example of a three-component reaction. The substrate scope of this reaction is consistent with generation of a triplet phosphinidene. In all, this study presents catalytic phosphinidene transfer to unsaturated organic substrates.