Activation of metal-bound η5-C5Me5groups to Diels–Alder addition of 3O2 and other dienophiles†
Abstract
Pt(η5-C5Me5)(PR3)I (PR3 = PPh3, PPhCy2, PPhMetBu) reacts with 3O2 to form the metal-bound endoperoxide Pt(η1,η2-C5Me5O2)(PR3)I; analogous reactions of Pt(η5-C5Me5)(PPh3)I with a variety of other dienophiles to form Pt(η1,η2-C5Me5CH2CHR)(PPh3)I (R = C(O)H, CO2Me, C(O)Et) in which the metal is anti to the incoming dienophile are indicative of direct Diels–Alder addition to the η5-C5Me5 ring.