Investigation of Flavinium Salts as Catalysts for Intermolecular C(sp3)-H Amination

For several decades, the synthesis of pharmaceutical drugs and biologically active compounds has advanced rapidly. The prevalence of nitrogen atoms in these drug compounds has led synthetic chemists to develop efficient and cost-effective methods to form carbon-nitrogen bonds in new ways. Among several methods, C-H amination has received a tremendous amount of attention due to its potential in efficiency and selectivity. Despite this, organocatalytic intermolecular C-H amination has been underexplored compared to the other catalytic systems. In this thesis, I have investigated flavinium salts as catalysts for intermolecular C-H amination. The flavinium salt catalyst derived from flavin groups was capable of catalyzing intermolecular C(sp3)-H amination using PhINTces as the nitrogen source. However, the reactivity was lower than that of the previous iminium salt catalyst and the scope was limited to substrates with highly activated benzylic C-H bonds. Despite this, the observed trend of scope indicated that the flavinium salt catalyst might be going through the same mechanism as the iminium salt catalyst, through the biradical intermediate.