text]. The first general and highlyenantioselective organocatalytic Friedel-Craftsalkylation of indoles with simple alpha,beta-unsaturated ketones has been accomplished. Central to these studies has been the identification of a new catalyst amine salt, in which both the cation and the anion are chiral, that exhibits high reactivity and selectivity for iminium ion catalysis.
Electron-Withdrawing, Biphenyl-2,2′-diol-Based Compounds for Asymmetric Catalysis
作者:Elisa G. Gutierrez、Eric J. Moorhead、Eva H. Smith、Vivian Lin、Laura K. G. Ackerman、Claire E. Knezevic、Victoria Sun、Sharday Grant、Anna G. Wenzel
DOI:10.1002/ejoc.201000070
日期:——
Facile synthetic routes to a chiral chloro-substituted biphenyl-2,2′-diyl hydrogen phosphate and a chiral O,O-biphenyl-2,2′-diyl phosphoramidothioate are described. The performance of these compounds as catalysts for the hydrophosphonylation of imines and the Friedel–Crafts alkylation of indole was investigated. In the latter reaction, the chloro-substituted phosphoric acid derivative was found to
Ba black sheep: We have developed novel barium/binol catalysts prepared from alkaline earth metal amides and chiral binaphthol ligands. These catalysts effectively promoted the asymmetric Friedel–Crafts–typealkylationreactions of indoles with chalconederivatives. This is the first example of asymmetric Friedel–Crafts–typealkylationreactionsusingchiral Brønsted bases.
Asymmetric Friedel-Crafts Alkylation of Indole with Chalcones Catalyzed by Chiral Phosphoric Acids
作者:Arrigo Scettri、Rosaria Villano、Maria Acocella
DOI:10.3390/molecules14083030
日期:——
The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoricacid. Furthermore, the alkylation products can be obtained in much higher e.e.s after one only crystallization.
发现吲哚与查耳酮反应生成迈克尔型加合物,在手性 BINOL 型磷酸存在下以良好的效率(高达 98% 的产率)和中等的对映选择性(高达 52% ee)发生。此外,仅在一次结晶后可以以更高的 ee 获得烷基化产物。