Self-Assembled Bidentate Ligands for the Nickel-Catalyzed Hydrocyanation of Alkenes

摘要

Nitriles are versatile intermediates in organic synthesis as they can be transformed into a wide variety of useful compounds, such as amines, aldehydes, ketones, and a range of carboxylic acid derivatives. A particularly appealing method for their synthesis consists of the formal addition of HCN across a C=C double bond, commonly referred to as hydrocyanation. Although the reaction is most commonly catalyzed by catalysts incorporating (bidentate) phosphite or phosphinite ligands, the use of bidentate phosphine ligands has attracted considerable interest. Van Leeuwen and coworkers showed that bidentate ligands with bite angles of approximately 105° have a beneficial effect on the activity of catalysts for the hydrocyanation of terminal alkenes. The same research group was able to demonstrate that the use of electron-deficient ligands also leads to increased activity. However, catalytic hydrocyanation remains underdeveloped and most of the research in the area has focused on the DuPont adiponitrile process. In order to transform hydrocyanation into a synthetically useful reaction, it is of prime importance to develop more efficient catalyst systems.