报道了丙二酸亚丙二酸酯与吲哚的新型环化反应,它可有效地获得各种六氢咔唑。对映选择性形式是通过微调的配体/ Cu II催化剂实现的。光学活性的六氢咔唑包含三个季碳中心,并以高达99%的收率和大于99:1的dr以及高达大于99%的ee获得。该反应可以以克为单位进行,产物的立体选择性转化导致了来自Kopsia植物的一系列生物碱的核心结构。
Visible Light-Mediated C–H Difluoromethylation of Electron-Rich Heteroarenes
作者:Yi-Ming Su、Yu Hou、Feng Yin、Yue-Ming Xu、Yan Li、Xiaoqi Zheng、Xi-Sheng Wang
DOI:10.1021/ol501094z
日期:2014.6.6
A novel method for visible-light photoredox-catalyzed difluoromethylation of electron-rich N-, O-, and S-containingheteroarenes under mild reaction conditions is developed. Mechanistic investigation indicates that the net C–H difluoromethylation proceeds through an electrophilic radical-type pathway.
A highly efficient N,N′‐dioxide–NiII catalyst system for the catalytic [3+2] cycloaddition of indoles with epoxides through CC cleavage of oxiranes was accomplished under mild conditions. It provided a promising approach for chiral furo[3,4‐b]indoles in up to 98 % yield with up to 91 % enantiomeric excess (ee) and >95:5 diastereomeric ratio (d.r.).
一个高效Ñ,Ñ '二氧化物-镍II为吲哚与环氧化物至C催化的[3 + 2]环加成催化剂体系环氧乙烷的C ^裂解温和的条件下完成的。它为手性呋喃[3,4- b ]吲哚提供了一种有前途的方法,产率高达98%,对映体过量(ee)高达91%,非对映体比率(dr)大于95:5。
Access to Hexahydrocarbazoles: The Thorpe-Ingold Effects of the Ligand on Enantioselectivity
A novel cyclization reaction of methylenemalonate with indoles is reported, and it provides efficient access to a variety of hexahydrocarbazoles. The enantioselective version was realized by a finely tuned ligand/CuII catalyst. The optically active hexahydrocarbazoles contain three quaternary carbon centers and are obtained in up to 99 % yield with greater than 99:1 d.r. and up to greater than 99 %
报道了丙二酸亚丙二酸酯与吲哚的新型环化反应,它可有效地获得各种六氢咔唑。对映选择性形式是通过微调的配体/ Cu II催化剂实现的。光学活性的六氢咔唑包含三个季碳中心,并以高达99%的收率和大于99:1的dr以及高达大于99%的ee获得。该反应可以以克为单位进行,产物的立体选择性转化导致了来自Kopsia植物的一系列生物碱的核心结构。