Brønsted acid-catalyzed inverse electron-demand diels-alder reactions of 1,2-diazines
The discovery of Diels-Alder reaction by Otto Diels and Kurt Alder in 1928 marked an important development in synthetic organic chemistry. This [4+2] cycloaddition reaction has been used in a variety of ways over the years, from natural product synthesis to medicinal chemistry. The process produces derivatives of cyclohexane by the coordinated addition of a conjugated diene and a dienophile. As a subclass of Diels-Alder reactions, inverse electron-demand Diels-Alder (IEDDA) reactions are covered in this thesis, along with their intricate mechanisms and applications. IEDDA cycloaddition reactions have become more well-known recently, especially in the fields of chemical biology, bio-orthogonal reactions and the synthesis of complex molecules. These reactions generally have excellent regio- and stereoselectivity and they occur between electron-poor dienes and electron-rich dienophiles. They have been crucial in the synthesis of bioactive substances with potential use for the cancer treatment, such as halenaquinone and rhodexin A. Catalysts have become an effective means of promoting IEDDA reactions in the search for milder reaction conditions and higher yield. To modify the energy levels of dienes and increase reactivity, Brønsted acid catalyst has been used in this project. This study involves the investigation of pyridinium salts as Brønsted acid catalyst intended to reduce the LUMO energy levels of 1,2-diazines. The goal is to make diazines more reactive in IEDDA reactions, creating new pathways for the synthesis of a variety of complex molecules. By bridging the gap between difficult reaction conditions and effective IEDDA reactions, this project aims to increase the usefulness of this potent synthetic method in contemporary organic chemistry.