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DOI: 10.1055/s-0030-1260920
Asymmetric Strecker Reaction of Di- and Trifluoromethyl Ketoimines
Y.-L. Liu, T.-D. Shi, F. Zhou, X.-L. Zhao, X. Wang*, J. Zhou*
East China Normal University, Shanghai and Sichuan University, P. R. of China
Publication History
Publication Date:
19 August 2011 (online)
Significance
The enantioselective Strecker reaction of difluoromethyl or trifluoromethyl ketoimines was reported using a quinidine-derived bifunctional urea 1 as a catalyst to synthesize α-tetrasubstituted α-aminonitriles with a α-di- or -trifluoromethyl group. A similar thiourea-catalyzed Strecker reaction has already been reported by Enders and co-workers (Adv. Synth. Catal. 2010, 352, 3147) for the α-CF3-ketoimines, but the reaction time was long (5-22 d). In this article, the authors showed that good enantioselectivity could be obtained without additives, but the use of hexafluoroisopropanol permitted an acceleration of the reaction. The authors proved the utility of the enantioenriched α-CF2H or -CF3 α-tetrasubstituted α-aminonitrile by synthesizing an α-CF2H Cα-tetrasubstituted amino acid and a trifluoromethylated imidazolidinone without lost of enantioselectivity.