Ligand development in the Ni-catalyzed hydrocyanation of alkenes

Abstract

The addition of HCN to alkenes is a very useful reaction for the synthesis of functional organic substrates. Industrially the nickel-catalyzed hydrocyanation has gained considerable importance mainly because of the production of adiponitrile in the DuPont process. In this process the hydrocyanation of butadiene is carried out using aryl phosphite-modified nickel catalyst. Since the performance of organo-transition metal complexes is largely determined by the ligand environment of the metal, fundamental understanding and ligand development is of pivotal importance for any progress. This feature article gives an account of the development and application of different mono- and bidentate phosphorus-based ligands in the Ni-catalyzed hydrocyanation reaction of alkenes. Special attention will be paid to the development of insight and understanding of the ligand structural and electronic properties towards the improvement of the catalyst performance in terms of stability, activity, and selectivity.

Coinage Metal Complexes of Phosphonite Analogues of 2‐Diphenylphosphino‐1,1′‐binaphthyl (H‐MOP) and 2‐Diphenylphosphino‐2′‐methoxy‐1,1′‐binaphthyl (MeO‐MOP)

“…Chiral phosphonites are ligands with good π‐acceptor properties which have proven to be effective in nickel‐catalysed hydrocyanations, and rhodium‐catalysed hydroformylations and hydrogenations We have demonstrated that atropisomeric monophosphonites with a binaphthyl backbone, are particularly successful in the palladium‐catalysed asymmetric hydrosilylation of alkenes, capable of transforming methoxy‐substituted styrenes with far greater enantioselectivity than the phosphine ( S )‐2‐diphenylphosphino‐1,1′‐binaphthyl, known as ( S )‐H‐MOP. [4a] MOP ligands possess a phosphorus donor bound directly to a binaphthyl backbone – the H‐MOP series a has a hydrogen in the 2′ position of the lower naphthyl ring, whilst a methoxy group occupies that site in the b series to give MeO‐MOPs (ligands 1 – 3 , below); this difference has profound implications for the catalytic performance of the ligands .…”

“…Chiral phosphonites are ligands with good π-acceptor properties which have proven to be effective in nickel-catalysed hydrocyanations, [1] and rhodium-catalysed hydroformylations [2] and hydrogenations. [3] We have demonstrated that atropisomeric monophosphonites with a binaphthyl backbone, [4] are particularly successful in the palladium-catalysed asymmetric hydrosilylation of alkenes, capable of transforming methoxy-substituted styrenes with far greater enantioselectivity than the phosphine (S)-2-diphenylphosphino-1,1′-binaphthyl, known as (S)-H-MOP.…”

Enantioselective Nickel‐Catalyzed Hydrocyanation using Chiral Phosphine‐Phosphite Ligands: Recent Improvements and Insights

“…[6] Recently,w ed isclosedafirst generalp rotocolf or the highly enantioselective (up to 97% ee)N i-catalyzed hydrocyanation of various vinylarenes employing the chiral phosphine-phosphitel igand 3 and TMSCN/MeOH as an in situ source of HCN (Scheme 1). [7] Modularligands of this type are accessible in only af ew steps [8] and have proven their utility alreadyi nn umerous transitionm etal-catalyzed reactions.…”

Bor‐Lewis‐Säure‐katalysierte Transferhydrocyanierung α‐ und α,β‐substituierter Styrole

“…[1] Im Gegenzug ist der Einsatz von gasfçrmigem HCN (Sdp. Im industriellen Maßstab ist die übergangsmetallkatalysierte Hydrocyanierung von Alkenen unter Verwendung von Blausäure (HCN) die Methode der Wahl zur Herstellung von Nitrilen.…”