system has been developed for the enantioselective aza‐Friedel–Craftsreaction of isatin‐derived ketimines with indoles. A series of enantiomerically enriched 3‐indolyl‐3‐aminooxindoles containing a tetrasubstituted stereocenter were obtained in up to 99% yield with up to 96% ee. Furthermore, control experiments provide a fundamental sight into the mechanism of the reaction.
Catalytic Asymmetric Aza-Friedel–Crafts-Type Reaction of Indoles with Isatin-Derived <i>N</i>-Cbz-Ketimines Using a Chiral Bis(Imidazolidine)-Containing NCN-Pincer Palladium Catalyst
作者:Takayoshi Arai、Kensuke Araseki、Junki Kakino
DOI:10.1021/acs.orglett.9b03148
日期:2019.11.1
A chiralbis(imidazolidine)-containing NCN-pincer palladium complex (tBu-PhBidine-Pd-OTf) was an efficient catalyst for the aza-Friedel–Crafts-type reaction of 1H-indoles with isatin-derived N-Cbz-ketimines to give chiral 3-aminobisindole compounds having differently oxidized indole units with high enantioselectivities.