Stereochemistry modulates the catalytic hydrogenolysis of nitrile-substituted cyclopropanes
作者:Daphne E. González-Juárez、J. Benjamín García-Vázquez、Violeta Zúñiga-García、Joel J. Trujillo-Serrato、Oscar R. Suárez-Castillo、Pedro Joseph-Nathan、Martha S. Morales-Ríos
DOI:10.1016/j.tet.2012.06.025
日期:2012.9
The study of Raney-Ni catalyzed chemo- and regioselective hydrogenolysis of diastereomeric nitrile-substituted spirocyclopropyloxindoles is presented. The chemoselectivity outcome of the reaction is remarkably influenced by the relative stereochemistry of the nitrile-substituted spirocyclopropyloxindoles. Chemo- and high regioselective cyclopropane ring-opening occurs from the syn diastereomers to
One-pot synthesis of conformationally restricted spirooxindoles
作者:Martha S. Morales-Ríos、Daphne E. González-Juárez、Ernesto Rivera-Becerril、Oscar R. Suárez-Castillo、Pedro Joseph-Nathan
DOI:10.1016/j.tet.2007.05.009
日期:2007.8
the 3R∗,8R∗ diastereomers being thermodynamically favored under the basic reaction conditions for three- and five-membered rings, and the 3R∗,8S∗ diastereomer in the case of six-memberedrings, as predicted by DFT calculations. The relative stereochemistry was supported by 2D NMR spectra and X-ray crystal structural analysis. The conformational rigidity of the spirocycloalkyloxindoles in solution was
通过一锅碱基介导的双烷基化策略,使用1-甲基-3-乙腈三恶灵以快速,方便的方式,从容易获得的起始原料以中高收率成功合成了非对映异构的三元,五元和六元螺环烷基烷基吲哚。发现非对映体的选择取决于反应条件和螺环烷基环的大小,在三元和五元环的基本反应条件下,3 R *,8 R *非对映异构体在热力学上是有利的,而3 R ∗,8秒∗DFT计算所预测的六元环的非对映异构体。相对立体化学由2D NMR光谱和X射线晶体结构分析支持。基于NMR实验和理论DFT方法,确定了螺环烷基氧吲哚在溶液中的构象刚度。
Catalyst and solvent-free cyclopropanation of electron-deficient olefins with cyclic diazoamides for the synthesis of spiro[cyclopropane-1,3′-indolin]-2′-one derivatives