Diastereoselective Synthesis of 2-Amino-1-Pyrrolines via Gold-Catalyzed N-Alkenylation of Isoxazolines and Rearrangement

The gold-catalyzed synthesis of 2-amino-1-pyrrolines from isoxazolines and ynamides has been explored as a retrosynthetic alternative to conventional approaches that overcomes traditional limitations and expands the structural diversity of these important heterocycles. Optimization of gold-catalyzed C–N bond formation and subsequent rearrangement is described in addition to reaction scope and methods for the preparation of NH-isoxazolines. Mechanistic insight into the rearrangement pathway is discussed and supports the observed control of relative stereochemistry. The use of chiral auxiliaries for the preparation of chiral non-racemic 2-amino-1-pyrrolines is also examined.