Reduction of N-Allylamides by LiAlH4: Unexpected Attack of the Double Bond with Mechanistic Studies of Product and Byproduct Formation
| Autor: | Anne Staubitz, Christin M. L. Schmitz, Birk Thiedemann |
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| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular chemistry.chemical_classification Steric effects Magnetic Resonance Spectroscopy Double bond Chemistry Organic Chemistry Amide reduction Nuclear magnetic resonance spectroscopy Alkenes Photochemistry Amides Reduction (complexity) Solvent chemistry.chemical_compound Amide Lithium Compounds Solvents Aluminum Compounds Two-dimensional nuclear magnetic resonance spectroscopy |
| Zdroj: | The Journal of Organic Chemistry. 79:10284-10295 |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/jo501907v |
| Popis: | The reduction of secondary allyl amides with LiAlH4 can lead to a concomitant reduction of the double bond. Previously, an excess of LiAlH4 in hazardous solvents was used for the reduction. This work discusses optimized reaction conditions in tBuOMe as a safe solvent, with only a 1.5-fold excess of LiAlH4, without reduction of the double bond in most cases. (1)H and (2)D NMR spectroscopic studies give evidence for the mechanism of the reduction of the amide as well as the double bond: Amide reduction generally precedes double bond reduction. Sterically hindered allylamides are an exception. They are reduced considerably more slowly at higher temperatures, and double bond reduction is observed before amide reduction has gone to completion. |
| Databáze: | OpenAIRE |
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