| Abstract
| - Os(η2-8-quinolyl)Cl(CO)(PPh3)2 is readily brominated in the 5-position of the quinolyl ligand. The resulting brominated complex can be lithiated by treatment with BuLi, and the lithiated intermediate, through reaction with appropriate electrophiles, allows placement in the 5-position of diverse groups, including tributyltin and acetyl.
- Bromination of the 8-quinolyl ligand in thecomplex Os(η2-8-quinolyl)Cl(CO)(PPh3)2 (1) occurs selectively in the 5-position, para to the osmium−carbonbond. Treatment of the brominated product, Os(η2-8-quinolyl-Br-5)Cl(CO)(PPh3)2 (2a), with BuLi gives anintermediate lithiated quinolyl species Os(η2-8-quinolyl-Li-5)Cl(CO)(PPh3)2 (3), which undergoes further reactions typical of aryllithium reagents. Treatment withthe representative electrophiles n-BuBr, Bu3SnCl, andMe2NC{O}Me produces Os(η2-8-quinolyl-Bu-5)Cl(CO)(PPh3)2 (4), Os(η2-8-quinolyl-SnBu3-5)Cl(CO)(PPh3)2 (5),and Os(η2-8-quinolyl-C{O}Me-5)Cl(CO)(PPh3)2 (6), respectively. Crystal structures of Os(η2-8-quinolyl-Br-5)I(CO)(PPh3)2 (2b) and Os(η2-8-quinolyl-[C{O}Me]-5)Cl(CO)(PPh3)2 (6) have been determined.
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