108036-64-2Relevant articles and documents
Reversible and Diastereospecific Insertion of 2-Acetamidoacrylic Methyl Ester into the Metal-Hydrogen Function of Chiral Clusters
Mani, Darjusch,Schacht, Hans-Thomas,Powell, Anne K.,Vahrenkamp, Heinrich
, p. 2245 - 2252 (2007/10/02)
The chiral hydrido metal clusters (μ3-RC)CoMM'Cp(CO)8H (R = Me, Ph; M = Ru, Os; M'= Mo, W) (1a-5a) react with the prochiral alanine precursor 2-acetamidoacrylic methyl ester by insertion into the M-H function and substitution of a CO group.In a diastereospecific reaction cluster adducts 1b-5b with a five-membered M-C-N-C-O ring are formed which contain an M-C ?-bond involving a tertiary carbon atom.This has been confirmed by a crystal structure determination of the RuCoMo compound 1b.Deuteration experiments have ascertained that the reaction is of the Markownikow-type.The enamide substrate is regenerated with CO or PPh3, it is not hydrogenerated with H2.A partial enantiomer separation of the insertion products is possible by chromatography over triacetylcellulose.The subsequent elimination of the enamide by CO or PPh3 is accompanied by nearly quantitative racemisation of the cluster. - Key Words: Clusters, hydrido metal / Insertion, diastereospecific
