Rearrangement of Metallabenzynes to Chlorocyclopentadienyl Complexes
journal contribution
posted on 2015-03-09, 00:00 authored by Jiangxi Chen, Ka-Ho Lee, Tingbin Wen, Feng Gao, Herman
H. Y. Sung, Ian D. Williams, Zhenyang Lin, Guochen JiaTreatment of the osmabenzyne complex
Os{C-C(SiMe3)C(CH3)-C(SiMe3)CH−}Cl2(PPh3)2 with Mo(CO)6 in refluxing benzene produced
the η5-chlorocyclopentadienyl
complex Os{η5-C5HCl(CH3)(SiMe3)2}Cl(CO)(PPh3) and Mo(CO)5(PPh3). A computational study suggests that
the chlorocyclopentadienyl complex is most likely produced via the
carbene intermediate Os{C(C(SiMe3)C(CH3)-C(SiMe3)CH−)}Cl2(CO)(PPh3) formed by a migratory insertion reaction
of the osmabenzyne complex Os{C-C(SiMe3)C(CH3)-C(SiMe3)CH}Cl2(CO)(PPh3). DFT calculations show that the relative thermal stability of metallabenzynes Os(C-CHCHCHCH)Cl2(L)2 and the corresponding isomeric carbene complexes
Os{C(−CHCHCHCH−)}Cl2(L)2 as well as the chlorocyclopentadienyl complexes
Os(η5-C5ClH4)Cl(L)2 (L = CO, phosphine, pyridine, amine) is strongly dependent
on ligand L.
