Reductive Ring Opening of Cyclic Amines: Pyrrolidines and Beyond

Abstract The reductive ring opening of cyclic amines is a powerful strategy for transforming cyclic structures into entirely different molecular frameworks, with significant potential application in synthetic and medicinal chemistry. Previously reported methods have been primarily limited to highly strained substrates such as aziridines and azetidines. In this study, we report a novel approach for generating carbon-centered radicals upon ring opening from less strained cyclic amines, particularly pyrrolidines, using Lewis acid and photoredox catalysis. Notably, while still in its early stages, this method shows potential applicability to larger rings, such as six- and seven-membered systems. Here, we detail the development, scope, and potential of this method, demonstrating efficient and selective reactions of a range of cyclic amines. 1 Introduction 2 Recent Examples of Reductive Ring Opening of Pyrrolidines 3 Our Working Hypothesis and Ring Opening of Pyrrolidines 4 Conclusion