Reactivity of mixed organozinc and mixed organocopper reagents: 14. Phosphine-nickel catalyzed aryl-allyl coupling of (n-butyl)(aryl)zincs. Ligand and substrate control on the group selectivity and regioselectivity
作者:Melike Kalkan、Ender Erdik
DOI:10.1016/j.jorganchem.2016.05.014
日期:2016.9
regioselectivity in the allylation of mixed (n-butyl)(aryl)zinc reagents in THF depends on the nickel catalyst type and also on nature of the allylic substrate. Allylation of (n-butyl)(phenyl)zinc reagent with alkyl substituted primary allylic chlorides and acetates in the presence of NiCl2(dppf) catalysis affords the phenyl coupling product with γ-selectivity. However, allylation with aryl substituted
混合(正丁基)(芳基)锌试剂在THF中烯丙基化时的基团选择性和区域选择性取决于镍催化剂的类型以及烯丙基底物的性质。在NiCl 2(dppf)催化下,将(正丁基)(苯基)锌试剂与烷基取代的伯烯丙基氯化物和乙酸酯进行烯丙基化,得到具有γ-选择性的苯基偶联产物。然而,与芳基取代的主要烯丙基底物的烯丙基化会导致在NiCl 2(dppf)催化下具有中等α选择性的苯基和烷基偶联产物,而在NiCl 2的存在下以α选择性形成苯基偶联产物。(Ph 3 P)2催化。这种新的NiCl 2在室温下用(dppf)催化的(n-丁基)(芳基)锌试剂与烷基取代的伯烯丙基氯化物进行γ-选择性芳基烯丙基化的协议为(芳基)2 Zn试剂的烯丙基化提供了一种原子经济的替代方法。提出了Ni催化(正丁基)(芳基)锌试剂的烯丙基化反应的基团选择性和区域选择性对催化剂配体和底物的依赖性的机理。