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.
A New Type of Bis(sulfonamide)-Diamine Ligand for a Cu(OTf)<sub>2</sub>-Catalyzed Asymmetric Friedel–Crafts Alkylation Reaction of Indoles with Nitroalkenes
作者:Jing Wu、Xincheng Li、Fan Wu、Boshun Wan
DOI:10.1021/ol201914r
日期:2011.9.16
Chiral bis(sulfonamide)-diamine served as new type of ligand for a Cu(OTf)2-catalyzed asymmetricFriedel–Craftsalkylation reaction of indoles with nitroalkenes. The desired products were obtained with up to 99% yield and 97% ee.
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