Readily available ferrocenyl-phosphinite ligands for Ru(II)-catalyzed enantioselective transfer hydrogenation of ketones and fabrication of hybrid heterojunctions

Abstract

A variety of phosphinite based on ferrocenyl moiety possessing central chirality have been screened as ligands for ruthenium(II)-catalyzed transfer hydrogenation of acetophenone derivatives using iso-PrOH as the hydrogen source to afford the corresponding product, (R) or (S)-1-phenylethanol derivatives with high conversions and good enantioselectivities. These complexes were also employed in the asymmetric reduction of different prochiral ketones (up to 85% ee). A comparison of the catalytic properties of amino alcohols and other analogs based on ferrocenyl backbone is also discussed briefly. The structures of these ligands and their corresponding complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis. Furthermore, organic–inorganic hybrid heterojunctions were also fabricated by forming thin films of ruthenium(II) complexes on n-Si and evaporation of Au as front contact. Current–voltage (I–V) characteristics of the structures showed excellent rectification properties. Electrical parameters including ideality factor, barrier height and series resistance were determined using I–V and capacitance–voltage (C–V) data. Finally, photoelectrical properties of the structures were examined by means of a solar simulator with AM1.5 global filter.