97551-17-2Relevant academic research and scientific papers
Multistep oxidase-lyase reactions: Synthesis of optically active 2-hydroxyketones by using biobased aliphatic alcohols
Perez-Sanchez, Maria,Mueller, Christoph R.,DominguezdeMaria, Pablo
, p. 2512 - 2516 (2013/08/23)
Enzymatic multistep reactions are presently an important research field, from which integrated and efficient synthetic protocols can be created, accompanied by a diminished waste formation (avoiding downstream units operations). This article explores the benzaldehyde lyase (BAL) catalyzed crossed carboligation of benzaldehyde with different aliphatic aldehydes to afford optically active α-hydroxyketones. To this end, different biobased aliphatic alcohols were insitu oxidized to aldehydes by oxidase from Hansenula sp. and subsequently carboligated with benzaldehyde by BAL in the same reactor system. For short nonbranched aliphatic alcohols, moderate to high conversions in carboligations (15-99%) with excellent enantioselectivities (98-99%, R), were achieved. Both enzymes also exhibited activities at high concentrations of benzaldehyde (up to 200mM) and with butanol as cosolvent, albeit at the cost of lower conversions, presumably owing to kinetic reasons. After needed optimization of the biocatalyst (e.g., through genetic evolution, whole-cell setup) and the process setup (e.g., stepwise addition of substrates, reaction time), the herein reported concept might provide promising entries in the field of asymmetric synthesis, delivering useful building blocks starting from biobased materials, and in an integrative manner.
Asymmetric oxidation of enol phosphates to α-hydroxy ketones using Sharpless reagents and a fructose derived dioxirane
Krawczyk, Ewa,Mielniczak, Grazyna,Owsianik, Krzysztof,?uczak, Jerzy
, p. 1480 - 1489 (2013/01/15)
The asymmetric oxidation of a variety of differently substituted, acyclic and cyclic enol phosphates using the Sharpless AD-reagents AD-mix-α and AD-mix-β, and a fructose derived chiral ketone as a catalyst, afforded the corresponding α-hydroxy ketones in high enantioselectivity and good yield. The influence of steric and electronic factors of the substrates on the facial stereoselectivity in the reported oxidations was studied.
Asymmetric oxidation of enol phosphates to α-hydroxy ketones by?(salen)manganese(III) complex. Effects of the substitution pattern of enol phosphates on the stereochemistry of oxygen?transfer
Koprowski, Marek,?uczak, Jerzy,Krawczyk, Ewa
, p. 12363 - 12374 (2007/10/03)
This paper presents a study of enantioselective catalytic oxidation of a variety of differently substituted, cyclic (E) and acyclic (Z)-enol phosphates. The asymmetric oxidation of acyclic (Z)-enol phosphates containing alkoxy substituents in the phosphate group 2a, c, e-g, i, and j and Z-configured enol phosphates containing aryloxy substituents in the phosphate group 2b, d, and h afforded optically active α-hydroxy ketones 4a-j of opposite configuration with good to high enantioselectivity. The influence of electronic and steric effects of the enol phosphate substituents on the stereoselectivity of oxidation was studied.
α-Hydroxy ketones in high enantiomeric purity from asymmetric oxidation of enol phosphates with (salen) manganese(III) complex
Krawczyk, Ewa,Koprowski, Marek,Skowronska, Aleksandra,Luczak, Jerzy
, p. 2599 - 2602 (2007/10/03)
Optically active α-hydroxy ketones 4 have been prepared in high enantioselectivity by the catalytic, enantioselective oxidation of easily available and stable (E)-enol phosphates 2 by (salen) Mn(III) complex.
Preparation of Optically Active α-Acetoxyacylophenones via Enzyme Mediated Hydrolysis
Ohta, Hiromichi,Ikemoto, Mitsushi,Ii, Hiroyuki,Okamoto, Yasushi,Tsuchihashi, Gen-ichi
, p. 1169 - 1172 (2007/10/02)
Microorganisms that hydrolyzes α-acetoxyacylophenones were screened, and it was found that Pichia miso IAM 4682, a type culture belonging to yeast, gave the best results.The esterase of this microbe hydrolyzed (R)-acetates in a highly enantioselective manner.
