FACILE AND REVERSIBLE CO INSERTION INTO THE IR-CH3 BOND OF [IR4(CH3)(CO)8(MU(4)-ETA(3)-PH2PCCPH)(MU-PPH2)]

Reaction of [Ir4H(CO)10(mu-PPh2)) with BuLi, Ph2PC=CPh and then Mel gi ves [Ir4(CH3)(CO)8(mu4-eta3-Ph2PCCPh)(mu-PPh2)], which undergoes a rev ersible two-step CO insertion under extremely mild conditions to yield Ir4{(CH3C(O)}(CO)8-(mu4:eta3-Ph2PCCPh)(mu-PPh2)] as the final product ; the structures of both species have been established by X-ray diffra ction studies.