Reactions of a Dihydride−Osmium(IV) Complex with Aldehydes: Influence of the Substituent at the Carbonyl Group

The reactivity of the dihydride−acetone complex [OsH 2 (η 5 -C 5 H 5 )(κ 1 -OCMe 2 )(P i Pr 3 )]BF 4 ( 1 ) toward cinnamaldehyde, isovaleraldehyde, and benzaldehyde has been investigated. In addition to the reduction of the aldehydes, three different reaction patterns have been observed, which depend on the alkenyl, alkyl, and aryl nature of the substituent at the carbonyl group. As a result, the complexes [Os(η 5 -C 5 H 5 )(CO)(η 2 -PhCH═CH 2 )(P i Pr 3 )]BF 4 ( 2 ), [Os(η 5 -C 5 H 5 )(CO) 2 (P i Pr 3 )]BF 4 ( 3 ), and [ OsH(η 5 -C 5 H 5 ){C 6 H 4 C( O)H}(P i Pr 3 )]BF 4 ( 6 ) have been isolated and characterized, including the X-ray structure of 2 .