Transition Metal Catalysis for Heteroarene Dearomatization and Natural Product Synthesis (2022-09-09)

Abstract

Non-aromatic nitrogen containing heterocycles such as dihydropyridines, tetrahydropyridines and piperidines are common structural motifs in drug molecules and natural products. Due to their widespread presence in bioactive molecules, synthesis of such heterocycles has attracted significant attention of the synthetic community. Despite the past efforts, methods for the catalytic stereoselective synthesis of dihydropyridines and piperidines is limited. We will discuss our studies toward the synthesis of dihydropyridines and related partially saturated heteroarenes through dearomatization of corresponding aromatic heteroarenes. These reactions are catalyzed by variety of transition metal catalysts and proceed in excellent yield, regioselectivity and enantioselectivity, and tolerate a wide range of functional groups such as ester, ketone, amide, halogen and primary alcohol. Chemoselective reactions of the remaining double bonds of the reaction products, dihydroheteroarenes, enables their conversion to saturated nitrogen heterocycles. Factors that influence the reaction yield, enantioselectivity, regioselectivity of the reactions as well as applications of these transition metal catalyzed reactions to natural product synthesis will also be discussed.