Formamidines - Versatile Ligands for Zinc-Catalyzed Hydrosilylation and Iron-Catalyzed Epoxidation Reactions

In the present study the abilities of catalysts modified by formamidine ligands have been examined in the zinc-catalyzed hydrosilylation of ketones and the iron-catalyzed epoxidation of stilbene. In case of hydrosilylation diethylzinc combined with easily accessible formamidine ligands allow for the efficient reduction of various aryl and alkyl ketones. By using a convenient in situ catalyst system high turnover frequencies up to more than 1.000 h(-1) and a broad functional group tolerance were achieved. Moreover, the formamidine ligands were successfully applied in the iron-catalyzed epoxidation of stilbene with hydrogen peroxide in good yield and chemoselectivity.