A Chiral Nonracemic Enolate with Dynamic Axial Chirality: Direct Asymmetricα-Methylation ofα-Amino Acid Derivatives
2000; Wiley; Volume: 39; Issue: 12 Linguagem: Inglês
10.1002/1521-3773(20000616)39
ISSN1521-3773
AutoresTakeo Kawabata, Hideo Suzuki, Yosikazu Nagae, Kaoru Fuji,
Tópico(s)Axial and Atropisomeric Chirality Synthesis
ResumoThe crucial intermediate A with a racemization barrier of 16 kcal mol−1 at −78 °C is proposed for the asymmetric α-methylation of 1 to give 2 in 81 % ee and 96 % yield (see scheme). The asymmetric α-methylation occurs in other amino acid derivatives (Dopa, Val, Leu, Trp, His, Tyr) in 78–93 % ee. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2000/z14334_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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