Absolute Autocatalytic Amplification under Heterogenous Phase Conditions Involving Subsequent Hydride Transfer and a Hemiacetal Intermediate. Issue 5 (5th February 2020)

• Record Type: Journal Article
• Authors: Rotunno, Giuseppe; Petersen, Dirk; Amedjkouh, Mohamed
• Is Part Of: ChemSystemsChem. Volume 2:Issue 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-02-05
• Subjects: amplification -- asymmetric synthesis -- autocatalysis -- chirality -- zinc; Synthetic biology -- Periodicals; Artificial cells -- Periodicals; Chemical systems -- Periodicals; Biochemistry -- Periodicals; Biotechnology -- Periodicals; 572
• DOI: 10.1002/syst.201900060
• Languages: English
• ISSNs: 2570-4206

Abstract

Abstract: Abstract : In contrast to the homogenous phase, absolute asymmetric amplification of pyridine alkanol is observed under heterogenous conditions. The reaction of iPr2 Zn vapor on a solid powder of pyridine carbaldehyde induced autocatalytic amplification of chirality providing the alkanol product with an enantiopurity up to 90 % ee. In this study, side products were identified and their formation is traced back to redox pathways involving hydride transfer, namely a chiral ester resulting most probably from a disproportionation of the starting aldehyde into a hemiacetal and subsequent hydride loss following a Claisen‐Tishchenko mechanism. These observations provide new perspectives in the elucidation of the mechanism of amplification of chirality in the Soai reaction. Abstract : Watch and learn : Absolute asymmetric amplification is observed for pyridine alkanol by reaction with iPr2 Zn vapor under heterogenous conditions. Beside the chiral alkanol, formation of a chiral ester is observed and is identified as a subsequent Claisen‐Tishchenko product of a hemiacetal intermediate during a Soai absolute amplification.