Experimental and Computational Studies Unraveling the Peculiarity of Enolizable Oxoesters in the Organocatalyzed Mannich-Type Addition to Cyclic <i>N</i>-Acyl Iminium Ions

γ− and δ-Oxoesters are easily available starting materials that have been sparingly used in some organocatalyzed reactions proceeding with a high enantioselectivity. In our experimentation we found that the use of these compounds as the enolizable (nucleophilic) component in organocatalyzed Mannich-...

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Bibliographic Details
Main Authors: Andrea Menichetti, Sebastiano Di Pietro, Valeria Di Bussolo, Lucilla Favero, Mauro Pineschi
Format: Article
Language:English
Published: MDPI AG 2020-04-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/25/8/1903
Description
Summary:γ− and δ-Oxoesters are easily available starting materials that have been sparingly used in some organocatalyzed reactions proceeding with a high enantioselectivity. In our experimentation we found that the use of these compounds as the enolizable (nucleophilic) component in organocatalyzed Mannich-type reactions using in situ-generated cyclic <i>N</i>-acyl iminium ions gave low diastereoselectivity and low to moderate values of enantioselectivity. This significant drop of facial selectivity with respect to simple aliphatic aldehydes has been rationalized by means of density functional theory (DFT) calculations.
ISSN:1420-3049