- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
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Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
- Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
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- Metal-Free Dehomologative Oxidation of Arylacetic Acids for the Synthesis of Aryl Carboxylic Acids
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A novel I2-promoted direct conversion of arylacetic acids into aryl carboxylic acids under metal-free conditions has been described. This remarkable transformation involves decarboxylation followed by an oxidation reaction enabled just by using DMSO as the solvent as well as an oxidant. Notably, aryl carboxylic acids are isolated by simple filtration technique and obtained in good to excellent yields. This protocol is free from chromatographic purification, which makes it applicable for large-scale synthesis.
- Kalmode, Hanuman P.,Vadagaonkar, Kamlesh S.,Shinde, Suresh L.,Chaskar, Atul C.
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p. 3781 - 3786
(2017/04/11)
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- Modulation of (non)linear optical properties in tripodal molecules by variation of the peripheral cyano acceptor moieties and the π-spacer
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A series of twelve tripodal push-pull molecules with a central triphenylamine donor and peripheral cyano substituted acceptors has been prepared. These molecules possess systematically altered π-linkers as well as cyano acceptors. Based on the experimental properties measured by differential scanning calorimetry, electrochemistry, one and two photon absorption/emission spectroscopy, supported by the DFT calculations, thorough structure-property relationships were elucidated.
- Cvejn,Michail,Polyzos,Almonasy,Pytela,Klikar,Mikysek,Giannetas,Fakis,Bure
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supporting information
p. 7345 - 7355
(2015/08/11)
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- Synthesis, crystal structure, and resolution of [10](1,6)pyrenophane: An inherently chiral [n]cyclophane
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A synthetic approach to a set of three inherently chiral [n]cyclophanes, [n](1,6)pyrenophanes (29a-c, n = 8-10) was investigated. Progress toward 29a was thwarted by the failure of the key dithiacyclophane-forming reaction. For the next higher homologue, the synthesis was completed, but the desired [9](1,6)pyrenophane (29b) could only be partially separated from an isomeric pyrenophane, [9](1,8)pyrenophane (28b), and an unidentified byproduct. Work aimed at the synthesis of the next higher homologue resulted in the isolation of a 7:4 mixture of [10](1,8)pyrenophane (28c) and [10](1,6)pyrenophane (29c), which could not be separated by column chromatography or crystallization. However, single-crystal X-ray structures of 28c and 29c were obtained after manual separation of two crystals with different morphologies from the same batch of crystals obtained from the 7:4 mixture of 28c and 29c. The pyrene system of 29c was found to have a gentle end-to-end bend as well as a significant longitudinal twist. Short intermolecular C(sp3)- H???π contacts (2.64 to 2.76 A) between H-atoms on the bridge and the centroids of three of the four six-membered rings of the pyrene system of a neighboring pyrenophane of like chirality give rise to the formation of single enantiomer columns. From a DNMR study of the mixture of 28c and 29c, the bridge in [10](1,8)pyrenophane (28c) was found to undergo a conformational flip from one side of the pyrene system to the other with ΔG = 14.9 ± 0.2 kcal/mol. A two-stage preparative HPLC protocol was subsequently developed for the separation of 28c and 29c (Chiralpak AD-H column) and then the enantiomers of 29c (Chiralcel OJ-H column). This enabled the measurement of their optical rotations and CD spectra.
- Yang, Yixi,Mannion, Michael R.,Dawe, Louise N.,Kraml, Christina M.,Pascal, Robert A.,Bodwell, Graham J.
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experimental part
p. 57 - 67
(2012/03/10)
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- Poly-iodinated compounds, process for their preparation, contrast medium containing them
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The invention relates to novel poly-iodinated compounds of general formula: STR1 in which R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10, identical or different, are selected from an iodine atom, a group of formula STR2 provided that at least two of the R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 groups represent an iodine atom, utilizable in contrast media for radiography. The invention also relates to a process for the preparation of these compounds as well as a contrast medium containing them.
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