93922-51-1Relevant articles and documents
Biocatalytic Parallel Interconnected Dynamic Asymmetric Disproportionation of α-Substituted Aldehydes: Atom-Efficient Access to Enantiopure (S)-Profens and Profenols
Tassano, Erika,Faber, Kurt,Hall, Mélanie
, p. 2742 - 2751 (2018)
The biocatalytic asymmetric disproportionation of aldehydes catalyzed by horse liver alcohol dehydrogenase (HLADH) was assessed in detail on a series of racemic 2-arylpropanals. Statistical optimization by means of design of experiments (DoE) allowed the identification of critical interdependencies between several reaction parameters and revealed a specific experimental window for reaching an ′optimal compromise′ in the reaction outcome. The biocatalytic system could be applied to a variety of 2-arylpropanals and granted access in a redox-neutral manner to enantioenriched (S)-profens and profenols following a parallel interconnected dynamic asymmetric transformation (PIDAT). The reaction can be performed in aqueous buffer at ambient conditions, does not rely on a sacrificial co-substrate, and requires only catalytic amounts of cofactor and a single enzyme. The high atom-efficiency was exemplified by the conversion of 75 mM of rac-2-phenylpropanal with 0.03 mol% of HLADH in the presence of ～0.013 eq. of oxidized nicotinamide adenine dinucleotide (NAD+), yielding 28.1 mM of (S)-2-phenylpropanol in 96% ee and 26.5 mM of (S)-2-phenylpropionic acid in 89% ee, in 73% overall conversion. Isolated yield of 62% was obtained on 100 mg-scale, with intact enantiopurities. (Figure presented.).
A asymmetric catalytic synthesis of (R)- 4, 7 - dimethyl - 1 - Tetralone method
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Paragraph 0027; 0028; 0029, (2017/08/25)
The invention discloses a method for asymmetrically catalyzing and synthesizing (R)-4, 7-dimethyl-1-tetralone. According to the method, an asymmetrical Kumada cross coupling reaction is conducted on racemization 2-halogenated propionate ester catalyzed by bis oxazoline/ cobalt and a methyl phenyl grignard reagent, and (S)-P-toluene propionate ester 2 is firstly generated; then, (S)-P-toluene propionate ester 2 is reduced to (S)-P-toluene propyl alcohol 3 through diisobutylaluminium hydride (DIBAL-H), and then (R)-4-p-methylphenyl-1-amylene 5 is obtained through bromine generation and coupling with and vinyl grignard reagent; next, a hydroboration-oxidation reaction and a Dess-Martin oxidizing reaction are sequentially conducted, and (R)-4-p-methylphenyl valeraldehyde 6 is obtained; finally, oxidation is conducted through silver oxide, an intramolecular Fourier acyl reaction is conducted, and (R)-4,7-dimethyl-1-tetralone is obtained in a ring-closure synthesis mode. The synthesis route is simple and concise, 8 reactions are conducted in all, the total yield is 27%, and the optical purity of a product is 90%.
Asymmetric synthesis of (R)-ar-curcumene, (R)-4,7-dimethyl-l-tetralone, and their enantiomers via cobalt-catalyzed asymmetric Kumada cross-coupling
Wu, Lin,Zhong, Jiang-Chun,Liu, Shi-Kuo,Liu, Fei-Peng,Gao, Zi-Dong,Wang, Min,Bian, Qing-Hua
, p. 78 - 83 (2015/12/31)
An efficient and concise asymmetric synthesis of (R)-(+)-ar-curcumene, (R)-4,7-dimethyl-l-tetralone, and their enantiomers was accomplished. The key step to construct the stereogenic benzylmethyl centers of these natural products is the cobalt-catalyzed a
