Monodentate N-Ligand-Directed Bifunctional Transition-Metal Catalysis: Highly Enantioselective Friedel-Crafts Alkylation of Indoles with Nitroalkenes
作者:Fengfeng Guo、Guoyin Lai、Shunshun Xiong、Sujing Wang、Zhiyong Wang
DOI:10.1002/chem.201000540
日期:2010.6.11
A role beyond base: A highly efficient, asymmetric Friedel–Craftsalkylation of indoles with nitroalkenes is presented that uses simple nitrogen compounds combined with Schiff base zinc(II) complexes as bifunctional catalysts (see scheme). The nitrogen compounds here play a crucial role as ligands as well as their traditional role as bases.
Chiral Phosphoric Acid Catalyzed Asymmetric Friedel–Crafts Alkylation of Indoles with Nitroolefins
作者:Hong-Ying Tang、Zhong-Biao Zhang
DOI:10.1080/10426507.2010.536189
日期:2011.10
Abstract Asymmetric Michael-type Friedel–Crafts (F–C) alkylations of indoles with nitroolefins catalyzed by a chiral H8-BINOL-based phosphoricacid were investigated. The reactions took place very smoothly in the presence of only 5 mol-% of catalyst at room temperature to afford the desired F–C alkylation products in good yields and with moderate enantioselectivities. GRAPHICAL ABSTRACT
A chiral bicyclic skeleton-tethered bipyridine–Zn(OTf)<sub>2</sub> complex as a Lewis acid: enantioselective Friedel–Crafts alkylation of indoles with nitroalkenes
enantioselective Friedel–Craftsalkylation of indoles with trans-β-nitroarylalkenes in an enantioselective manner at elevated temperature. Indoles reacted smoothly with β-nitroarylalkenes to generate the corresponding 3-(2-nitroalkyl)indoles in good to excellent yields (up to 94%) with moderate to excellent enantioselectivities (up to 91%). The stereochemical outcome of the product fromindole and trans-β-nitrostyrene
Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to Indolylnitroalkenes
作者:Junwei Xing、Guihua Chen、Peng Cao、Jian Liao
DOI:10.1002/ejoc.201101648
日期:2012.2
bioactive structures. Most approaches to access chiral indolylnitroethanes involve organocatalyzed or metal-catalyzed asymmetric FriedelCrafts reaction of indoles with nitroalkenes. We have developed an efficient approach to optically pure a-aryl-3-indolylnitroethanes through rhodium-catalyzed asymmetric 1,4-addition of arylboronicacids to indolylnitroalkenes. Excellent yields (up to 99?%) and enantiomeric