Platinum(II) complexes incorporating racemic and optically active 1-alkyl-3-phospholenes and 1-propyl-phospholane P-ligands: Synthesis, stereostructure, NMR properties and catalytic activity

Racemic and optically active 1-propyl- and 1-butyl-3-methyl-3-phospholene oxides, as well as 1-propyl-3-methylphospholane oxides were converted after deoxygenation to the corresponding phosphine-borane and phopshine-platinum complexes. Stereostructure of the novel platinum complexes with a propyl group on the phosphorus atom was evaluated by quantum chemical calculations. The complexes displayed characteristic properties regarding their NMR spectra and showed unusual regioselectivity as catalysts in the hydroformylation of styrene derivatives. Ee-s up to 21% were obtained in the presence of optically active Pt-complex precursors.