N-Oxyl-Radical-Catalyzed Intermolecular Aminooxygenation of Styrenes and Inter/intramolecular Aminoalkoxylation of Homoallylic Alcohols

摘要

By taking advantage of the redox cycle between the reductive N-oxyl radical and its oxidative oxoammonium counterpart, the N-oxyl-radical-catalyzed intermolecular aminohydroxylation of styrenes with N-fluorobenzenesulfonimide was developed. Various vinyl arenes were aminohydroxylated in moderate to excellent yields with high regio-and diastereoselectivities by using environmentally benign H2O as the oxygen source. In addition, the sequential inter/intramolecular aminoalkoxylation of homoallylic alcohols was also achieved under anhydrous conditions, which allowed the exclusive synthesis of pharmaceutically useful 2-aryl-3-amino-disubstituted tetrahydrofurans.