Study On Visible Light Photoredox-Catalyzed Decarboxylative Coupling Of ?-amino Acids Or ?-keto Acids With Nitrones

On the basis of previous research of C-C bond formation at N-? position via ?-aminoalkyl radicals and enantioselective synthesis of vicinal amino alcohols by merging photoredox catalysis with Lewis acid catalysis,two further methods of novel visible light-induced photoredox-catalyzed decarboxylative coupling reactions of ?-amino acids or ?-keto acids with nitrones have been developed.Some highlight results and light photoredox-catalyzed decarboxylative coupling of ?-amino acids with nbrief contents of this thesis are showed as follows:1.Visible itronesAs a class of important structural motifs,vicinal diamines are commonly existed in natural products,pharmaceuticals,chiral anxiliaries and ligands.Based on the previous research,a visible light-induced decarboxylative coupling reaction of ?-amino acids with nitrones by using Ir-complex as photoredox catalyst has been developed.A series of ?-amino hydroxylamines has been synthesized under mild conditions which can be converted into vicinal diamines conveniently by using zinc powder as reductant.Furthermore,this method has been applied to the synthesis of an antihistamine Mepyramine.2.Visible light photoredox-catalyzed decarboxylative coupling of a-keto acids with nitrones?-amino ketones are important structural motifs present in various bioactive molecules.During the research of visible light photoredox-catalyzed decarboxylative coupling of ?-amino acids with nitrones,a photocatalytic oxidative decarboxylation of?-keto acids followed by a radical addition of carbonyl radicals to nitrones has been discovered.Thus a new method for synthesis of a-amino ketones has been developed.