Ferrocenylindium Reagents in Palladium‐Catalyzed Cross‐Coupling Reactions: Asymmetric Synthesis of Planar Chiral 2‐Aryl Oxazolyl and Sulfinyl Ferrocenes

Abstract

AbstractThe preparation of ferrocenylindium species and palladium‐catalyzed cross‐coupling reactions for the synthesis of monosubstituted and planar chiral 1,2‐disubstituted ferrocenes is described. Triferrocenylindium reagents (Fc3In) are efficiently prepared in a one‐pot procedure from ferrocenes by lithiation and transmetallation to indium using InCl3. The palladium‐catalyzed cross‐coupling reactions of Fc3In (40 mol%) with a variety of organic electrophiles (aryl, heteroaryl, benzyl, alkenyl and acyl halides) in THF at 80 °C overnight provided a wide variety of monosubstituted ferrocenes in good to excellent yields. This methodology allowed the stereoselective synthesis of planar chiral 2‐aryl‐1‐oxazolylferrocenes and 2‐aryl‐1‐sulfinylferrocenes, which are of interest in asymmetric catalysis.magnified image