Heterogeneous versus Homogeneous Copper(II) Catalysis in Enantioselective Conjugate-Addition Reactions of Boron in Water
作者:Taku Kitanosono、Pengyu Xu、Shū Kobayashi
DOI:10.1002/asia.201300997
日期:2014.1
reported for the conjugate addition of boron. Heterogeneous cat. 1 also gave high yields and enantioselectivities with some substrates and also gave the highest TOF (43 200 h−1) for an asymmetric conjugate‐addition reaction of boron. In addition, the catalyst systems were also applicable to the conjugate addition of boron to α,β,γ,δ‐unsaturated carbonyl compounds, although such reactions have previously
我们已经开发了Cu II催化的硼在水中与α,β-不饱和羰基化合物和α,β,γ,δ-不饱和羰基化合物的对映体共轭加成反应。与先前报道的需要有机溶剂的Cu I催化相反,发现手性Cu II催化在水中有效地进行。已经开发了三种催化剂体系:催化剂。1:具有手性配体L 1的Cu(OH)2;猫。2:具有配体L1的Cu(OH)2和乙酸;和猫。3:具有配体L1的Cu(OAc)2。而猫。1是异构系统,猫。2和猫。3是同质系统。我们测试了27种α,β-不饱和羰基化合物和α,β-不饱和腈化合物,包括无环和环状α,β-不饱和酮,无环和环状β,β-二取代的烯酮,无环和环状α,β-不饱和酯(包括其β,β-二取代形式)和无环α,β-不饱和酰胺(包括其β,β-二取代形式)。我们找到那只猫。2和猫。图3显示了几乎所有底物的高产率和对映选择性。值得注意的是,没有报道过能以高收率和高对映选择性耐受所有这些底物的催化剂。异类猫。1