title: Iron-catalyzed oxidative tandem reactions with TEMPO oxoammonium salts: synthesis of dihydroquinazolines and quinolines.
abstract: A straightforward iron-catalyzed divergent oxidative tandem synthesis of dihydroquinazolines and quinolines from N-alkylanilines using a TEMPO oxoammonium salt as a mild and nontoxic oxidant has been developed. Fe(OTf)2 was the Lewis acid catalyst of choice for the formation of dihydroquinazolines, whereas FeCl3 led to better results for the synthesis of quinolines. This divergent approach implies that, for both syntheses, direct oxidative functionalization of a α-C(sp(3))-H bond of the N-alkylanilines occurs, leading to C-N bond formation or C-C bond formation upon homocondensation or reaction with simple olefins, respectively. Cyclization followed by a final oxidation generates these classes of interesting bioactive heterocycles in one synthetic transformation. Additionally, the one-pot multicomponent synthesis of quinolines from anilines, aldehydes, and olefins has also been successfully developed under these mild oxidative conditions.
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Rohlmann
authors.forename: Tobias
authors.initials: T
authors.lastname: Stopka
authors.forename: Heinrich
authors.initials: H
authors.lastname: Richter
authors.forename: Olga
authors.initials: O
authors.lastname: García Mancheño