Platinum Phosphinito Catalysts for Nitrile Hydration

Synthetic Applications of the Parkins Nitrile Hydration Catalyst [PtH{(PMe2O)2H}(PMe2OH)]: A Review

“…α-hydroxynitriles. Unfortunately, the hydration rates for these substrates were very low in comparison to those observed with other nitriles, and only a few turnovers could be achieved [82,83]. The poor reactivity observed was ascribed to the low stability of the cyanohydrin substrates, which slowly equilibrate in solution with HCN and the corresponding aldehyde or ketone (Scheme 23), and the irreversible coordination of the cyanide anion to platinum leads to the deactivation of the catalyst.…”

Secondary Phosphine Oxides: Bifunctional Ligands in Catalysis

“…More common mechanisms were collected by Knapp et al, but in their work on the ethyl analog of 30 they could not find further proof for a mechanism. [77] The scope of the reaction has been enlarged to both more sensitive and less reactive substrates by De Vries et al [78] An attempt to asymmetric catalysis failed due to racemization of the product. Recently, Virgil, Grubbs, et al replaced the SPOÀ HÀ OPS in 30, as shown in Scheme 3 for 12, by a large number of diphosphine ligands in a high-throughput screening and in this way obtained cationic complexes that were far more active than 30.…”

Coordination chemistry and catalysis with secondary phosphine oxides

“…With this system a wide range of nitriles could be hydrated under relatively mild conditions, sometimes in pure water. 179,203 Despite the above results, most of the work has been carried out by using ruthenium(II) complexes 13,195 since the first report of Tyler and coworkers a few years ago, 104 ( Figure 6) who employed the same dimethylphosphinous acid as a ligand to Ru-p-cymene (Scheme 91). This SPO was faster than other phosphorus ligands with hydrogen bond accepting capability and was able to hydrate many nitriles in water under neutral conditions.…”