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 language | English |
|---|---|
| Pages (from-to) | 1238-1244 |
| Number of pages | 7 |
| Journal | Organic and Biomolecular Chemistry |
| Volume | 17 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 1 Jan 2019 |
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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 journal › Article
TY - JOUR
T1 - Absolute asymmetric Strecker synthesis in a mixed aqueous medium
T2 - Reliable access to enantioenriched α-aminonitrile
AU - Miyagawa, Shinobu
AU - Aiba, Shohei
AU - Kawamoto, Hajime
AU - Tokunaga, Yuji
AU - Kawasaki, Tsuneomi
PY - 2019/1/1
Y1 - 2019/1/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85060957691&partnerID=8YFLogxK
U2 - 10.1039/c8ob03092h
DO - 10.1039/c8ob03092h
M3 - Article
C2 - 30656321
AN - SCOPUS:85060957691
VL - 17
SP - 1238
EP - 1244
JO - Organic and Biomolecular Chemistry
JF - Organic and Biomolecular Chemistry
SN - 1477-0520
IS - 5
ER -