biostudies-literatureLiu CNational Natural Science Foundation of China8369-8372https://www.ebi.ac.uk/biostudies/studies/S-EPMC9062002biostudies-literatureUnknown9(15)A novel and efficient copper-catalyzed synthesis of dihydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinoline derivatives has been developed by using 3-alkyl-1-alkylindolin-2-imine hydrochlorides as the building blocks. Furthermore, easy reduction of dihydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinolines with diisobutylaluminum hydride provided tetrahydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinoline derivatives in excellent yields. The present method shows some advantages including use of cheap cuprous chloride as the catalyst and tolerance of wide functional groups.RSC advances1-Alkyl-3-alkylindolin-2-imine hydrochlorides as useful building blocks in the copper-catalyzed synthesis of polycyclic indoline scaffolds.PMC906200221772108Yang HFu HLiu CZhu Cfalse1-Alkyl-3-alkylindolin-2-imine hydrochlorides as useful building blocks in the copper-catalyzed synthesis of polycyclic indoline scaffolds.A novel and efficient copper-catalyzed synthesis of dihydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinoline derivatives has been developed by using 3-alkyl-1-alkylindolin-2-imine hydrochlorides as the building blocks. Furthermore, easy reduction of dihydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinolines with diisobutylaluminum hydride provided tetrahydro-6<i>H</i>-indolo[2,3-<i>b</i>]quinoline derivatives in excellent yields. The present method shows some advantages including use of cheap cuprous chloride as the catalyst and tolerance of wide functional groups.2019-01-01T00:00:00Z2019 Mar2025-04-26T12:21:30.856Z2025-04-06T13:55:36.153ZS-EPMC90620023551870010.1039/c9ra00995g