FeCl2/TBAC efficiently catalyzes domino coupling reactions for constructing indoline-fused tetrahydroisoquinolines

FeCl2/TBAC has been found to be highly active for the construction of indoline-fused tetrahydroisoquinolines using aryltetrahydroisoquinolines and active methylene as simple reactants. The transformation was proposed to proceed via domino coupling reactions between C-sp3-H and C-sp3-H, and subsequently C-sp3-H and C-sp2-H, respectively. The EPR spectra have been acquired to analyse the catalytically active species, (Fe3+OO center dot) and Fe3+, which accelerated the reaction via HAT and SET processes, respectively.

Automated summary

FeCl2/TBAC was found to exhibit high catalytic activity for the synthesis of indoline-fused tetrahydroisoquinolines using aryltetrahydroisoquinolines and active methylene as reactants. The reaction proceeded through domino coupling reactions between C-sp3-H and C-sp3-H, and subsequently C-sp3-H and C-sp2-H. EPR spectroscopy revealed the presence of catalytically active species (Fe3+OO center dot) and Fe3+, which enhanced the reaction through HAT and SET processes, respectively.