Reactivity of silyl-substituted heterobimetallic iron–platinum hydride complexes: Part III. Alkyne insertions into the platinum–hydride bond and competition between μ-vinylidene and dimetallacyclopentenone formation

Abstract

Insertion of aliphatic 1-alkynes such as tert-butylacetylene, 1-hexyne or 1,6-heptadiyne into the Pt–H bond of the heterobimetallic hydride complex [(OC) 3Fe{Si(OMe) 3}(μ-dppm)Pt(H)(PPh 3)] ( 1) (dppm = Ph 2PCH 2PPh 2) leads to the formation of an isomeric mixture of μ-vinylidene complexes [(OC) 3Fe{μ-C C(H)R}(μ-dppm)Pt(PPh 3)] ( 2a: R = tert-Bu, 2b: R = n-Bu, 2c: R = (CH 2) 3–C CH) and dimetallacyclopentenones [(OC) 2Fe{μ-C(=O)CR CH}(μ-dppm)Pt(PPh 3)] ( 3a: R = tert-Bu, 3b: R = n-Bu, 3c: R = (CH 2) 3–C CH). The molecular structures of 2a and 3c have been determined by single-crystal X-ray diffraction.