Enantioselective Synthesis of Substituted Indoles Through Zirconium(IV)-Catalyzed Friedel–Crafts Alkylation
作者:José Pedro、Gonzalo Blay、Isabel Fernández、Carlos Vila
DOI:10.1055/s-0032-1317161
日期:——
Abstract The chiral complex of (R)-3,3′-Br2-BINOL and zirconium tert-butoxide catalyzes the Friedel–Craftsalkylation of indoles with enones bearing an alkyl or fluorinated group at the β-position to give indoles having a side chain at the C3 position with a tertiary stereogenic center in good yields and with excellent enantioselectivities. The chiral complex of (R)-3,3′-Br2-BINOL and zirconium tert-butoxide
Metal‐bound water molecules have recently been recognized as a new facet of soft Lewis acid catalysis. Herein, a chiral palladium aqua complex was constructed that enables carbon–hydrogen bonds of indoles to be functionalized efficiently. We embraced a chiral 2,2′‐bipyridine as both ligand and hydrogen‐bond donor to configure a robust, yet highly Lewis acidic, chiral aqua complex in water. Whereas the
Highly Enantioselective Friedel−Crafts Alkylations of Indoles with Simple Enones Catalyzed by Zirconium(IV)−BINOL Complexes
作者:Gonzalo Blay、Isabel Fernández、José R. Pedro、Carlos Vila
DOI:10.1021/ol0710820
日期:2007.6.1
Complexes of BINOL-based ligands with Zr(OtBu)4 catalyze the Friedel-Craftsalkylation reaction of indoles and pyrrole with nonchelating beta-substituted alpha,beta-enones at room temperature affording the expected products with good yields and ee above 95% in most of the studied examples.