Palladium-Catalyzed Stereoselective Hydrodefluorination of Tetrasubstituted <i>gem</i>-Difluoroalkenes
Qiao Ma, Caroline Liu, Gavin Chit Tsui
Abstract
A highly stereoselective palladium(0)-catalyzed hydrodefluorination (HDF) of tetrasubstituted gem-difluoroalkenes is developed. By using catalytic Pd(PPh3)4 (2.5–5 mol %) and hydrosilane Me2PhSiH, various trisubstituted terminal (E)-monofluoroalkenes can be synthesized with excellent E/Z selectivity (>99:1) and good functional group tolerability. The key stereocontrol should be exerted by an ester-directed C–F bond oxidative addition step in the catalytic cycle.
Topics & Concepts
ChemistryStereoselectivityPalladiumCatalysisCombinatorial chemistryHalogenationOrganic chemistryFluorine in Organic ChemistryInorganic Fluorides and Related Compounds