197173-31-2Relevant academic research and scientific papers
Efficient generation and intramolecular cyclization reactions of acyl imines
DeNinno, Michael P.,Eller, Cynthia
, p. 6545 - 6548 (1997)
Acyl carbamates can be selectively reduced with diisobutyl aluminum hydride to provide high yields of N-acyl hemiaminals 1. With appropriate substitution, these intermediates undergo Lewis acid catalyzed intramolecular exo cyclization reactions to afford
The preparation and intra- and intermolecular addition reactions of acyclic N-acylimines: Application to the synthesis of (±)-sertraline
DeNinno,Eller,Etienne
, p. 6988 - 6993 (2007/10/03)
Intramolecular endo-cyclization reactions of N-acyliminium ions have seen wide application for the synthesis of heterocyclic compounds. The corresponding exocyclic variant, which would provide 1-aminotetralin derivatives, for example, has little precedent. We have discovered that acyclic N-acylcarbamates can be readily reduced to the corresponding N-acylhemiaminal derivatives in high yield using DIBAL as the reducing agent. These intermediates are remarkably stable and, if desired, can be purified and stored. The acyclic N-acylhemiaminals undergo both intra- and intermolecular nucleophilic addition reactions mediated by strong Lewis acids, such as TiCl4. Diastereoselectivity, induced either by a substituent on the newly formed ring, or by utilizing a chiral ester on the carbamic acid, was disappointingly low. This methodology was successfully applied to the synthesis of the racemic form of the marketed antidepressant sertraline.
