617-31-2Relevant articles and documents
Synthesis of Dicarboxylic Acids from Aqueous Solutions of Diols with Hydrogen Evolution Catalyzed by an Iridium Complex
Fujita, Ken-ichi,Toyooka, Genki
, (2020/07/13)
A catalytic system for the synthesis of dicarboxylic acids from aqueous solutions of diols accompanied by the evolution of hydrogen was developed. An iridium complex bearing a functional bipyridonate ligand with N,N-dimethylamino substituents exhibited a high catalytic performance for this type of dehydrogenative reaction. For example, adipic acid was synthesized from an aqueous solution of 1,6-hexanediol in 97 % yield accompanied by the evolution of four equivalents of hydrogen by the present catalytic system. It should be noted that the simultaneous production of industrially important dicarboxylic acids and hydrogen, which is useful as an energy carrier, was achieved. In addition, the selective dehydrogenative oxidation of vicinal diols to give α-hydroxycarboxylic acids was also accomplished.
α-Hydroxylation of Carboxylic Acids Catalyzed by Taurine Dioxygenase
Wetzl, Dennis,Bolsinger, Jennifer,Nestl, Bettina M.,Hauer, Bernhard
, p. 1361 - 1366 (2016/04/20)
Enzymes still have a limited application scope in synthetic organic chemistry. To expand this, different strategies exist that range from the de novo design of enzymes to the exploitation of the catalytic capabilities of known enzymes by converting different substrates; denoted as substrate promiscuity. We harnessed the synthetic potential offered by the taurine dioxygenase (TauD) from Escherichia coli (E. coli) by studying its promiscuous catalytic properties in the hydroxylation of carboxylic acid substrates. TauD showed high selectivities in the hydroxylation reaction but reduced levels of activity (26 % conversion, >96 % ee). We enhanced the enzyme substrate scope and improved the conversions for the tested substrates by introducing a point mutation at position 206 (F206Y). The conversions of the improved catalyst increased by at least 140 % compared to that of the wild-type enzyme. The number of carboxylic acids that accepted by the enzyme variant doubled from four to eight carboxylic acids.
PROCESS FOR PREPARING 1,2-DIOLS FROM CARBONYL COMPOUNDS
-
Page/Page column 3, (2008/06/13)
1,2-diols can be obtained in good yields and in very high purity by a process of a) reacting a carbonyl compound of the general formula (I) with hydrocyanic acid to give the corresponding cyanohydrin, wherein R1 and R2 are each independently H, an optionally substituted straight-chain or branched C1-C18-alkyl radical, or an optionally substituted phenyl or C5-C6-cycloalkyl radical, b) subjecting the cyanohydrin obtained in process step a) to an acidic hydrolysis, and c) catalytically hydrogenating the 2-hydroxycarboxylic acid obtained from process step b) in the presence of a noble metal catalyst comprising ruthenium and rhenium.
