Styrene palladium-catalysed oxidation

Very few examples of the oxidation of olefins to ketones in ionic liquids have been reported. In one case, [C4Ciim][BF4] or [C4Ciim][PF6] were used in the palladium-catalysed oxidation of styrene to acetophenone with H2O2 as oxidant, however the concept of biphasic catalysis was not exploited and no attempts were made to recycle the catalyst.[131 The ionic liquid serves the purpose of a co-catalyst rather than that of a reaction medium. 

Figure 8.7 Palladium-catalysed oxidation of styrene in PEG-SCCO2.

Intermolecular bisamidation of cM-styrenes (112), catalysed by Pd /Pd, has been developed as a regio- and diastereo-selective process (Scheme 7). The reaction is believed to commence with an anfi-addition of Pd and phthalimide across the C=C bond. The resulting intermediate (113) with palladium in the preferred benzylic position is then oxidized by PhI(OPiv)2 to generate the Pd species (114), which undergoes an 5ivf2 reaction with the second nucleophile to afford the final diamide derivative (115). ... 

Asymmetric hydrosilylation of alkenes, catalysed by ferrocenylphosphine-palladium complexes, can be utilized in a synthesis of optically active alcohols from alkenes (Scheme 1). The initial optically active silane adducts are converted to alkyl pentafluorosilicates (1) which are then cleaved oxidatively, with retention of configuration, using peracid (c/. 3,132). Complex (2) was the best of several hydrosilylation catalysts examined using this, alcohols with enantiomeric purities of approx. 50% were obtained from norbornene and styrene as the alkenes. 

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