Binaphthol-Based Diphosphite Ligands in Asymmetric Nickel-Catalyzed Hydrocyanation of Styrene and 1,3-Cyclohexadiene: Influence of Steric Properties
作者:Jos Wilting、Michèle Janssen、Christian Müller、Martin Lutz、Anthony L. Spek、Dieter Vogt
DOI:10.1002/adsc.200600315
日期:2007.2.5
(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)
制备了一系列具有不同取代基的手性(R)-联萘酚基二亚磷酸酯配体,并将其应用于苯乙烯和1,3-环己二烯的不对称镍催化的氢氰化反应中,以研究其空间特性的影响。氢氰化反应的最佳空间特性在狭窄的窗口内。使用优化的配体,苯乙烯进行氢氰化可得到49%ee的完全转化率(Subs / Ni = 100),TON测为600。1,3-环己二烯的氢氰化可得到50%的转化率(Subs / Ni = 500)。优秀的ee为86%。这表明高ee s不仅可用于乙烯基芳烃,而且可用于不对称镍催化的氢氰化反应中的共轭二烯。