Abstract
Strong and confined imidodiphosphorimidate (IDPi) catalysts enable highly enantioselective substitutions of cyclic, aliphatic hemiaminal ethers with enol silanes. 2-Substituted pyrrolidines, piperidines, and azepanes are obtained with high enantioselectivities, and the method displays a broad tolerance of various enol silane nucleophiles. Several natural products can be accessed using this methodology. Mechanistic studies support the intermediacy of non-stabilized, cyclic N-(exo-acyl)iminium ions, paired with the confined chiral counteranion. Computational studies suggest transition states that explain the observed enantioselectivity.
Original language | English |
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Article number | e202115036 |
Journal | Angewandte Chemie - International Edition |
Volume | 61 |
Issue number | 9 |
DOIs | |
State | Published - 21 Feb 2022 |
Bibliographical note
Publisher Copyright:© 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
Keywords
- Lewis acids
- Mukaiyama–Mannich reaction
- N-acyliminium ions
- imidodiphosphorimidates
- organocatalysis