313699-07-9Relevant academic research and scientific papers
Asymmetric β-aminoethylation of ketones and nitriles with tosylaziridines employing the SAMP-hydrazone method
Enders, Dieter,Janeck, Carsten F.,Raabe, Gerhard
, p. 3337 - 3345 (2007/10/03)
The nucleophilic ring-opening of tosylaziridines with chiral aza-enolates is reported. The SAMP-/ RAMP-hydrazones 1a-h derived from aldehydes or ketones were reacted with tosylaziridine 2a to give the β-aminoethylated hydrazones 3a-h with good diastereoselectivity. Removal of the chiral auxiliary resulted in the formation of the γ-amino nitriles 4a-e or γ-amino ketones 6f-h in good yields and excellent enantiomeric excesses (ee ≥ 98%). Ring-opening of the enantiopure, benzyl-substituted tosylaziridine 2b with aza-enolates was achieved selectively at the less-substituted ring-carbon atom, again with excellent diastereoselectivity. Subsequent cleavage of the chiral auxiliary yielded the γ-benzyl-substituted γ-amino nitrile 4j or γ-amino ketone 6i with de,ee ≥ 98%, respectively. The relative and absolute configuration of the new stereogenic centre of the aminoethylated hydrazones 3a-j was determined by NOE measurements and confirmed by X-ray structure analysis on the Mosher amide of 6h.
