5447-74-5Relevant articles and documents
Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones
??d?o-Dobrowolska, Anna,Borowiecki, Pawe?,Heider, Johann,Kroutil, Wolfgang,Reiter, Tamara,Schühle, Karola,Szaleniec, Maciej,Tataruch, Mateusz,Telatycka, Natalia
, (2020/04/20)
An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).
Transition Metal-Free Alkyne-Aldehyde Reductive C?C Coupling trough Cascade Borylation/Olefin Isomerization
Khan, Imran,Luo, Zhibin,Xu, Yin,Xie, Jimin,Zhu, Weihua,Liu, Bin
, (2020/05/04)
A direct approach to γ-keto esters through cascade alkyne-aldehyde reductive C?C coupling of propargyl esters and aromatic aldehydes under transition-metal-free (TM-free) fashion was developed. Compared with multistep processes, this procedure provides a
Synthesis of Novel C 2-Symmetric Sulfur-Based Catalysts: Asymmetric Formation of Halo- and Seleno-Functionalized Normal- and Medium-Sized Rings
Jana, Sadhan,Kumar, Sangit,Rathore, Vandana,Verma, Ajay
supporting information, p. 1667 - 1672 (2019/08/28)
The synthesis of novel, highly functionalized, C 2 -symmetric sulfur-based catalysts is developed and their catalytic applications are explored in asymmetric bromo-, iodo- and seleno-functionalizations of alkenoic acids. This protocol provides
