A Useful Access to the Chemistry of the Indenyl-Osmium-Triisopropylphosphine Moiety

Complex OsH 3 Cl(P i Pr 3 ) 2 ( 1 ) reacts with indenyllithium to give OsH(η 5 -C 9 H 7 )(P i Pr 3 ) 2 ( 2 ), which affords ( 3 ) by treatment with methyl trifluoromethanesulfonate. In acetonitrile, complex 3 evolves to an equilibrium mixture of the acetonitrile adducts [Os(η 5 -C 9 H 7 )(NCCH 3 )-(P i Pr 3 ) 2 ]OTf ( 4 ) and [Os(η 5 -C 9 H 7 )(NCCH 3 ) 2 (P i Pr 3 )]OTf ( 5 ). The addition of 2,5-norbornadiene (NBD) to this mixture leads to [Os(η 5 -C 9 H 7 )(η 4 -NBD)(P i Pr 3 )]OTf ( 6 ). Complex 2 also reacts with I 2 and HBF 4, to give [OsHI(η 5 -C 9 H 7 )(P i Pr 3 ) 2 ]I ( 7 ) and [OsH 2 (η 5 -C 9 H 7 )(P i Pr 3 ) 2 ]BF 4 ( 8 ), respectively.