Site-selective oxidative-addition reactions in a heterometallic octanuclear carbido cluster compound. A reactivity parallel with mononuclear indenyliridium complexes

The reactions of triphenylsilane and allyl bromide with [PPN] 2 [Re 7 C(CO) 21 Ir(C 8 H 14 )(CO)] in refluxing THF afforded products in which the substrates were added selectively to the iridium center. The products [PPN] 2 [Re 7 C(CO) 21 Ir(H)(CO)(SiPh 3 )] (1) (77%) and [PPN] [Re 7 C(CO) 21 Ir(η 3 -C 3 H 5 (CO)] (2) (40%) were characterized by analytical and spectroscopic data. The analogous reactions in refluxing cyclohexane with the indenyl complex (η 5 -C 9 H 7 )Ir(C 8 H 14 )(CO) yielded (η 5 -C 9 H 7 ) Ir-(H)(CO)(SiPh 3 ) (3) (78%) and [(η 5 -C 9 H 7 )Ir(η 3 -C 3 H 5 )(CO)]Br (4) (86%), respectively, which were similarly characterized