Asymmetric synthesis of cyclic α-amino acid derivatives by the intramolecular reaction of magnesium carbenoid with an N-magnesio arylamine
2009; Elsevier BV; Volume: 20; Issue: 14 Linguagem: Inglês
10.1016/j.tetasy.2009.06.024
ISSN1362-511X
AutoresShintaro Mitsunaga, Tohru Ohbayashi, Shimpei Sugiyama, Takahito Saitou, Makoto Tadokoro, Tsuyoshi Satoh,
Tópico(s)Synthetic Organic Chemistry Methods
ResumoThe synthesis of pipecolic acid and homopipecolic acid derivatives was developed from ω-(2-aminophenyl)-1-chloroalkyl p-tolyl sulfoxides by treatment with i-PrMgCl. An intramolecular nucleophilic substitution reaction of a magnesium carbenoid with an N-magnesio arylamine is the key step of this reaction. Proline and pipecolic acid derivatives were also synthesized from ω-(arylamino)-1-chloroalkyl p-tolyl sulfoxides by the same chemistry. Starting from enantiomerically pure (1S,RS)-1-chloro-3-[2-(N-methylamino)phenyl]propyl p-tolyl sulfoxide, enantiomerically pure (R)-pipecolic acid derivative was obtained. The intramolecular nucleophilic substitution reaction of the magnesium carbenoid with N-magnesio arylamine was proven to take place with inversion of the carbenoid carbon. The stereochemistry of these reactions is also discussed.
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