π-Allyl-Palladium-Komplexe stabilisiert durch den tripodalen Sauerstoffliganden [(C5H5) Co{P( OMe) 2O}3]-II 1. Eliminierung statt C-C-Bindungsbildung bei der Reaktion mit resonanzstabilisierten Carbanionen 2

Article abstract of DOI:10.1016/0022-328X(96)06253-5

The reaction of the complexes [L_OMePd(propenyl] (1) and [L_OMePd(2-methyl-propenyl] (2) (L^-_OMe= [(C₅H₅)Co{P(OMe)₂O}₃]^-) with sodium malonate results in the formation of the anticipated C-C coupling products (2-R-C₃H₅)CH(CO₂Et)₂ while [L_OMePd{4-6-η-(3-oxo-cholestenyl)}] (4) and [L_OMePd{4-6-η-(cholestenyl)}] (5) react with eliminination to give the corresponding cholestadienes. With sodium 2-acetylcyclopentanoate (Na acp), ligand substitution takes place in the reaction with 1-3 (3 = [L_OMePd(2-^tbutyl-propenyl)]) to give complexes of the type [(2-R-propenyl)Pd(acp)]. Their stability depends on the substituent of the allyl group. While [(propenyl)Pd(acp)] decomposes at room temperature, [(2-^tbutyl-propenyl)Pd(acp)] and [(2-methyl-propenyl)Pd(acp)] are air stable compounds which could be isolated.