Complexes including acetylides formed from 3-diphenylphosphinocamphor and platinum or palladium

Abstract

Treatment of lithiated D-camphor with a half molar equivalent of PPh2Cl gives the 3-diphenylphosphino enolate anion [PPh2(C10H14O)]- as the only phoshorus-containing species. Treatment of lithiated D-camphor with one equivalent of PPh2Cl gives some of the enolate anion but the main product is the3-exo substituted camphor derivative 3-exo-PPh2(C10H15O) together with some of the 3-endo-substituted derivative. On storage of the solution, the 3-endo substituted derivative becomes the main product with some of the 3-exe-substituted derivative still present. Treatment of a solution of the enolate ion with Na2PdCl4. 4H,O gives [Pd((PPh2)C10H14O)2] or with PtCl2(cyclo-octa-1,5-diene), cis- [Pt{(PPh2) C10H14O}2] is formed. Treatment of these bis-chelate complexes with hydrogen chloride opens up the chelate rings reversibly, giving dichloro-complexes of type [MCl1{(PPh2)C10H15O)2 ](M = Pd (trans-isomer) M = Pt (cis-isomer)).