Absolute asymmetric Strecker synthesis in a mixed aqueous medium: Reliable access to enantioenriched α-aminonitrile

Shinobu Miyagawa, Shohei Aiba, Hajime Kawamoto, Yuji Tokunaga, Tsuneomi Kawasaki

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Without using chiral sources, the Strecker reaction of achiral hydrogen cyanide, p-tolualdehyde and benzhydrylamine gave enantioenriched l- or d-N-benzhydryl-α-(p-tolyl)glycine nitriles with up to >99% ee in a mixed solvent of water and methanol. Therefore, total spontaneous resolution of α-aminonitriles could occur through a prebiotic mechanism of α-amino acid synthesis. Moreover, it was demonstrated that the repetition of partial dissolution and crystallization of a suspended conglomerate of aminonitrile under solution-phase racemization could generate the enantiomeric imbalance to afford, in combination with the amplification of chirality, an enantioenriched product in every case. Among the 73 experiments that were carried out, d- and l-enriched isomers occurred 36 and 37 times, respectively. This stochastic behavior, under achiral or racemic starting conditions, meets the requirements of the spontaneous absolute asymmetric Strecker synthesis. The implications of the present results for the origin of chirality of α-amino acids are discussed.

Original languageEnglish
Pages (from-to)1238-1244
Number of pages7
JournalOrganic and Biomolecular Chemistry
Volume17
Issue number5
DOIs
Publication statusPublished - 1 Jan 2019

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Chirality
chirality
amino acids
Hydrogen Cyanide
hydrocyanic acid
Amino Acids
Prebiotics
Nitriles
nitriles
synthesis
glycine
Crystallization
Isomers
Glycine
Amplification
Methanol
repetition
dissolving
Dissolution
isomers

Cite this

Miyagawa, Shinobu ; Aiba, Shohei ; Kawamoto, Hajime ; Tokunaga, Yuji ; Kawasaki, Tsuneomi. / Absolute asymmetric Strecker synthesis in a mixed aqueous medium : Reliable access to enantioenriched α-aminonitrile. In: Organic and Biomolecular Chemistry. 2019 ; Vol. 17, No. 5. pp. 1238-1244.
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Absolute asymmetric Strecker synthesis in a mixed aqueous medium : Reliable access to enantioenriched α-aminonitrile. / Miyagawa, Shinobu; Aiba, Shohei; Kawamoto, Hajime; Tokunaga, Yuji; Kawasaki, Tsuneomi.

In: Organic and Biomolecular Chemistry, Vol. 17, No. 5, 01.01.2019, p. 1238-1244.

Research output: Contribution to journalArticle

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