Hydrogen Bonding Phase-Transfer Catalysis with Ionic Reactants: Enantioselective Synthesis of γ-Fluoroamines
Giulia Roagna, David M. H. Ascough, Francesco Ibba, Anna Chiara Vicini, Alberto Fontana, Kirsten E. Christensen, Aldo Peschiulli, Daniel Oehlrich, Antonio Misale, Andrés A. Trabanco, Robert S. Paton, Gabriele Pupo, Véronique Gouverneur
Abstract
-urea catalyst. This process, which highlights the ability of hydrogen bonding phase-transfer catalysts to couple two ionic reactants, affords enantioenriched γ-fluoroamines in high yields. Mechanistic studies underline the role of the catalyst for phase-transfer, and computed transition state structures account for the enantioconvergence observed for mixtures of achiral azetidinium diastereomers. The N-substituents in the electrophile influence the reactivity, but the configuration at nitrogen is unimportant for the enantioselectivity.