Reactions of trans- and cis-Dichlorobis(benzonitrile)platinum(II) with Acetylacetonate and Benzoylacetonate Carbanions. Formation of N-Acetyl β-Ketoamine Complexes by the Acetyl Group Migration

Article abstract of DOI:10.1246/bcsj.54.1077

trans-Dichlorobis(benzonitrile)platinum(II) reacted with twice the molar amount of thallium(I) acetylacetonate and benzoylacetonate in dichloromethane at room temperature to afford mainly N-acetyl β-ketoamine chelates, (1a and 3a).This N,O-chelate structure of 1a was determined by X-ray analysis.Reactions of cis- gave C-acetyl and C-benzoyl β-ketoamine chelates, , together with other minor products.Formation of these β-ketoamine chelates is explained by the nucleophilic reactions of the β-diketonate carbanions at the coordinated cyanide carbon atom, followed by migration of the acetyl group or the methine proton of the nucleophiles onto the imino nitrogen atom formed during these reactions.In the presence of free β-diketones, migration of the acyl group was generally suppressed; this led to high yields of C-acyl complexes especially in reactions of cis-.In each case, the reaction proceeded with retention of the geometrical configuration around the central metal atom.The structures of other products, including a compound obtained by acid hydrolysis of 1a, were explored and discussed, based on IR and 1H NMR data.