Oxidative Addition von Aldehyden und Schiffbasen an Ru3(CO)12

Abstract

Oxidative Addition of Aldehydes and Schiff Bases to Ru3(CO)12Aldehydes show a wide variation of their reactive behaviour towards Ru3(CO)12. Aliphatic and simple aromatic aldehydes form simple oxidative addition products Ru3(CO)10(μ‐H)(μ‐RC = O) (1) either not at all or in low yields as impure compounds, while under forcing conditions dinuclear ruthenium μ‐carboxylate complexes or the hydride H2Ru4(CO)13 are formed. Electron‐rich aldehydes give good yields of cluster type 1 (R = p‐MeOC6H4, p‐Me2NC6H4, ferrocenyl). Schiff bases behave similarly, their oxidative addition products being Ru3(CO)10(μ‐H)(μ‐RC = NR′) (10, R = C6H5, p‐MeOC6H4, p‐Me2NC6H4, R′ = C6H5, p‐MeC6H4). Of the ortho‐substituted benzaldehydes, the methoxy compound produces clusters 6 and 7 resulting from aldehyde oxidative addition and aromatic ortho metalation. Salicylaldehyde and its p‐tolylimine give the compounds Ru3(CO)8(μ‐η2‐OC6H4CH = X)2 (9, 11, X = O, NC6H4Me) with a bridging phenolate and a terminally bound aldehydic O or Schiff base NR function. 3‐Pyridinecarbaldehyde reacts quickly with Ru3(CO)12 to give products 8 derived from pyridine CH rather than aldehyde CH oxidative addition. The crystal structures of 9 and 11 were determined.