KF/Al2O3 Mediated Aza-Michael Addition of Indoles to Electron-Deficient Olefins

KF/Al2O3 efficiently catalyzes aza-Michael addition of indole and 3-methylindole to a variety of electron-deficient conjugated alkenes such as α,β-unsaturated ketones, amides and nitriles. The N-alkylation adducts are produced in good to excellent yields and relatively in short times. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency.