Enantioselective Intramolecular Hydroarylation of Alkenes via Directed C−H Bond Activation
作者:Hitoshi Harada、Reema K. Thalji、Robert G. Bergman、Jonathan A. Ellman
DOI:10.1021/jo801098z
日期:2008.9.1
Highly enantioselective catalytic intramolecular ortho-alkylation of aromatic imines containing alkenyl groups tethered at the meta position relative to the imine directing group has been achieved using [RhCl(coe)2]2 and chiral phosphoramidite ligands. Cyclization of substrates containing 1,1- and 1,2-disubstituted as well as trisubstituted alkenes were achieved with enantioselectivities >90% ee for
已经使用 [RhCl(coe)2]2 和手性亚磷酰胺配体实现了含有链烯基的芳族亚胺的高度对映选择性催化分子内邻位烷基化,该烯基系在相对于亚胺导向基团的间位。对含有 1,1- 和 1,2- 二取代以及三取代烯烃的底物进行环化,每种底物类别的对映选择性 > 90% ee。具有 Z-烯烃异构体的底物环化比具有 E-烯烃异构体的底物更有效。这进一步使含有 Z/E-烯烃混合物的某些底物通过 Rh 催化的烯烃异构化和 Z-异构体的优先环化实现高度立体选择性的分子内烷基化。