14203-59-9Relevant articles and documents
Combining Photo-Organo Redox- and Enzyme Catalysis Facilitates Asymmetric C-H Bond Functionalization
Zhang, Wuyuan,Fueyo, Elena Fernandez,Hollmann, Frank,Martin, Laura Leemans,Pesic, Milja,Wardenga, Rainer,H?hne, Matthias,Schmidt, Sandy
supporting information, p. 80 - 84 (2019/01/04)
In this study, we combined photo-organo redox catalysis and biocatalysis to achieve asymmetric C–H bond functionalization of simple alkane starting materials. The photo-organo catalyst anthraquinone sulfate (SAS) was employed to oxyfunctionalise alkanes to aldehydes and ketones. We coupled this light-driven reaction with asymmetric enzymatic functionalisations to yield chiral hydroxynitriles, amines, acyloins and α-chiral ketones with up to 99 % ee. In addition, we demonstrate functional group interconversion to alcohols, esters and carboxylic acids. The transformations can be performed as concurrent tandem reactions. We identified the degradation of substrates and inhibition of the biocatalysts as limiting factors affecting compatibility, due to reactive oxygen species generated in the photocatalytic step. These incompatibilities were addressed by reaction engineering, such as applying a two-phase system or temporal and spatial separation of the catalysts. Using a selection of eleven starting alkanes, one photo-organo catalyst and 8 diverse biocatalysts, we synthesized 26 products and report for the model compounds benzoin and mandelonitrile > 97 % ee at gram scale.
CATALYTIC OXIDATION OF 3,5,5-TRIMETHYLCYCLOHEXA-3-ENE-1-ONE (?-ISOPHORONE) WITH HYDROGEN PEROXIDE TO AFFORD 2,6,6-TRIMETHYL-2-CYCLOHEXENE-1,4-DIONE (KETO-ISOPHORONE)
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Page/Page column 0059-0060; 0061-0063; 0064-0066; 0067-0068, (2018/06/15)
The present invention provides a novel process for producing 2,6,6-trimethyl-2-cyclohexene-1,4-dione (keto-isophorone) by catalytic oxidation of 3,5,5-trimethylcyclohexa-3-ene-1-one (β-isophorone) with hydrogen peroxide as the oxidant. In particular, the novel process includes phase transfer reagent in a biphasic system including an organic phase and an aqueous phase wherein the biphasic system includes 1) a tungsten polyoxyometallate as catalyst and hydrogen peroxide, and/or 2) a mixture of a) a mineral acid, b) hydrogen peroxide, and c) a metal tungstate.
Two catalytic systems of l-proline/Cu(II) catalyzed allylic oxidation of olefins with tert-butyl hydroperoxide
Yu, Peng,Zhou, Yin,Yang, Yingwei,Tang, Ruiren
, p. 65403 - 65411 (2016/07/26)
The nontoxic and water-soluble l-proline combined with two different forms of copper(ii): recoverable Cu-Al hydrotalcite-like compounds (Cu-Al HTLcs) and water-soluble CuCl2, as a heterogeneous catalytic system (l-proline/Cu-Al HTLcs) and two-phase catalytic system (l-proline/CuCl2) to catalyze allylic oxidation with tert-butyl hydroperoxide. The results showed that l-proline/Cu(ii) is highly active for oxidizing isophorone (IP) into ketoisophorone (KIP). Maximum catalytic effects were afforded respectively under the optimal reaction conditions, which obtained 77.9% IP conversion with 74.3% KIP selectivity catalyzed by l-proline/Cu-Al HTLcs and 73.5% conversion with 81.6% selectivity by l-proline/CuCl2. Recycling experiments of the two catalytic systems of l-proline/Cu(ii) showed they are stable and recyclable for at least six cycles with appreciable catalytic activity. And various hydrocarbons could be smoothly transformed into corresponding ketones with satisfactory conversion and selectivity by the two catalytic systems.