Palladium-NHC catalyzed enantioselective synthesis of fused indolines via inert C(sp3)-H activation

Abstract

New sterically hindered chiral N-heterocyclic carbene (NHC) ligands were used in palladium catalysis to bring about a highly enantioselective C(sp 3)-H activation on the methylene site of a cycloalkane moiety. The intramolecular coupling reaction of a prochiral N-aryl-N-cycloalkyl methyl carbamate required high temperatures (140-160 °C) and afforded highly enantioenriched trans-2,3-fused indolines. © Schweizerische Chemische Gesellschaft.