Recent Advancements in the Synthesis, Functionalization, and Applications of Nitrogen-Containing Heterocycles

Nitrogen-containing heterocycles are prolific throughout the sciences. Notably, the various branches of organic chemistry have dedicated decades of research to the synthesis, functionalization, and applications of N-heterocyclic compounds. Therefore, technology related to the development of methodologies for the synthesis, derivatization, or applications of nitrogenated compounds which exhibit novel bond disconnects or functions are of high interest. Our attention was focused on: unearthing methodologies which exploit transition metal-stabilized carbenes for the synthesis and functionalization of N-heterocycles; the total synthesis of biologically active alkaloids via resourceful retrosynthetic disconnects; the synthesis and discovery of N-heterocyclic/pnictogen based ionic liquid materials for various alternative energy applications.

Consequently, by utilizing carbene migratory insertion chemistry catalyzed by various transition metals, the synthesis of five-membered N-heterocyclic compounds via a (4+1)-cyclization disconnect was discovered and optimized. Additionally, employing a similar mechanistic disconnect the carbon-hydrogen functionalization of existing nitrogen-containing heterocycles was realized and briefly investigated. Furthermore, employing a (2+1)-cyclization/ring expansion strategy the synthesis of five- and seven-membered heterocyclic structures was recognized through metal-stabilized carbenoids. In a complimentary fashion to the development of methodologies accessing functionalized N-heterocycles, progress towards the synthesis of cyclopiazonic acid-derived alkaloids was enacted, assembling synthons which were investigated for a convergent retrosynthetic disconnect. Finally, through collaborative efforts, the amalgamation of organic synthesis and various sciences allowed for the identification of several task-specific ionic liquid materials.