Copper Complexes of Chiral Tetradentate Binaphthyl Schiff-Base Ligands: Syntheses, X-ray Crystal Structures and Activity in Catalytic Asymmetric Cyclopropanation of Alkenes
作者:Chi-Ming Che、Hoi-Lun Kwong、Wai-Cheung Chu、Kin-Fai Cheng、Wing-Sze Lee、Hing-Sun Yu、Chi-Tung Yeung、Keung-Kai Cheung
DOI:10.1002/1099-0682(200206)2002:6<1456::aid-ejic1456>3.0.co;2-h
日期:2002.6
1′-binaphthyl] and a series of chiral copper(II) complexes [CuL] were prepared in good or nearly quantitative yields. Some of the free ligands and the [CuL] complexes were structurally characterized by X-ray crystallography. Almost all the [CuL] complexes were found to be active catalysts for the asymmetric cyclopropanation of alkenes with ethyl or tert-butyl diazoacetate. Enantioselectivities of up to 77%
一些新的手性单体联萘席夫碱配体H2L [其中H2L = 2,2'-双(3-R1-5-R2-2-羟基亚苄基氨基)-1,1'-联萘]和一系列手性铜( II) 复合物 [CuL] 以良好或接近定量的产率制备。一些游离配体和 [CuL] 配合物通过 X 射线晶体学进行结构表征。几乎所有的 [CuL] 配合物都被发现是烯烃与重氮乙酸乙酯或叔丁基重氮乙酸乙酯不对称环丙烷化反应的活性催化剂。观察到高达 77% ee 的对映选择性。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)