Dynamic Kinetic Resolution of Aldehydes by Hydroacylation

Abstract

We report ad ynamic kinetic resolution (DKR) of chiral 4-pentenals by olefin hydroacylation. Ap rimary amine racemizes the aldehyde substrate via enamine formation and hydrolysis.Then, acationic rhodium catalyst promotes hydroacylation to generate a,g-disubstituted cyclopentanones with high enantio-and diastereoselectivities. Figure 1. Resolutions of chiral aldehydes by hydroacylation. Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Advances and applications of chiral resolution in pharmaceutical field

“…The general metal catalyzed racemization methods include 115 : (1) racemization achieved by hydrogen transfer reaction: (2) racemization produced by the formation of ‐allyl. Among them, the complexes of rhodium 116 (the first report of aldehydes by hydroacylation through DKR), palladium 117 and ruthenium 118 show an outstanding racemic catalytic performance. In recent years, the coupling of enzymes and transition metals has attracted a lot of attention.…”

Challenges and Opportunities in Multicatalysis

“…Ru-/P450-catalyzed orthogonal relay of reversible olefin cross-metathesis and substrate-selective epoxidation of alkenes The design principles of the above-described system of cooperating reversible olefin metathesis with selective olefin epoxidation resemble the working principles of dynamic kinetic resolution reactions (DKR). [99][100][101][102] In the latter, a dynamic equilibrium between two enantiomers of a substrate is maintained, but one enantiomer undergoes a subsequent reaction selectively. For instance, a secondary alcohol continues to be reversibly oxidized-reduced to maintain the racemic composition of the mixture in the presence of a hydrogen-borrowing catalyst, but one enantiomer of the alcohol continuous to undergo a selective acylation in the presence of a lipase, leading in the end to a quantitative conversion of a racemic alcohol to an enantiomerically pure ester.…”

Cobalt ferrite magnetic nanoceramics as an efficient nanocatalyst for the oxidation of olefins in the presence of molecular O2 as an environmentally safe oxidant

“…21 To increase and improve a catalyst efficiency, it is critical to use auxiliary catalysts or additives, which are catalyst ligands. 22 For the reductive activation of O 2 , aldehyde has been widely reported as a reducing agent in oxidation, where the catalysts involved are often magnetic nanoceramics 23 and SiO 2complex supported on magnetic nanoceramics. 24 Nasseri et al 25 reported efficient selective oxidation of benzyl alcohols with CoFe 2 O 4 @SiO 2 @Co(III) salen complex nanoparticle in the presence of isobutyraldehyde as an oxygen acceptor.…”

“…Therefore, it is favorable to suggest a strategy to perform the reactions using a non‐toxic oxidant and a short reaction at room temperature, saving energy 21 . To increase and improve a catalyst efficiency, it is critical to use auxiliary catalysts or additives, which are catalyst ligands 22 . For the reductive activation of O 2 , aldehyde has been widely reported as a reducing agent in oxidation, where the catalysts involved are often magnetic nanoceramics 23 and SiO 2 ‐complex supported on magnetic nanoceramics 24 …”