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Binaphthol‐Based Diphosphite Ligands in Asymmetric Nickel‐Catalyzed Hydrocyanation of Styrene and 1,3‐Cyclohexadiene: Influence of Steric Properties
Author(s) -
Wilting Jos,
Janssen Michèle,
Müller Christian,
Lutz Martin,
Spek Anthony L.,
Vogt Dieter
Publication year - 2007
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200600315
Subject(s) - hydrocyanation , chemistry , steric effects , nickel , styrene , catalysis , ligand (biochemistry) , organic chemistry , copolymer , polymer , biochemistry , receptor
Abstract A series of chiral ( R )‐binaphthol‐based diphosphite ligands with different substituents was prepared and applied in the asymmetric nickel‐catalyzed hydrocyanation of styrene and 1,3‐cyclohexadiene to investigate the influence of their steric properties. The optimum steric properties for the hydrocyanation reaction lie within a narrow window. With the optimized ligand, hydrocyanation of styrene gave full conversion (Subs/Ni=100) with 49 % ee , the TON was determined to be 600. Hydrocyanation of 1,3‐cyclohexadiene gave 50 % conversion (Subs/Ni=500) with an excellent ee of 86 %. This demonstrates that high ee s are not only accessible for vinylarenes but also for conjugated dienes in the asymmetric nickel‐catalyzed hydrocyanation.