Crystal structure and Hirshfeld surface analysis of 1,2-ethylene-bis(para-methylpyridinium) dichromate as a new selective and mild agent in oxidation of alcohols

Abstract

1,2-Ethylene-bis(para-methyl pyridinium) dichromate, (C 14 H 18 N 2) [Cr 2 O 7 ], is used as a new oxidizing agent in conversion of some alcohols to their corresponding carbonyl compounds in CH 3 CN solvent and also under solvent-free conditions. In both procedures, high conversion percentages are observed. However, a much shorter reaction time is achieved in solvent-free conditions. For allylic alcohols, the C = C bond is not oxidized and the examined saturated alcohol in this work (i.e. cyclo-hexanol) remains intact, which illustrates the mild nature of reagent used. The structure of the reagent is investigated by single-crystal X-ray diffraction analysis. The C-H • • • O and O • • • π interactions are the most important features of crystal packing, which are visualized by the Hirshfeld surface map.

Decarboxylative Oxidation of Carboxylic Acids Using Photocatalysis and Copper Catalysis

“…The product (57.5 mg, 82% isolated yield) was isolated by eluant EtOAc/PE (1:9) as yellow liquid. The spectra match the reported literature [3] . Compound 2d was prepared following the standard procedure B.…”

“…1 But, most of them are limited for phenylacetic acid or α-hydroxyphenylacetic acid type substrates as phenyl group could greatly stabilize the intermediate generated from the decarboxylation process. On the other hand, with the rapid development of photocatalytic decarboxylative reactions, a wide range of α-amino, α-oxy, benzylic, and even simple alkyl radicals could be generated from carboxylic acids and used for further transformations, such as decarboxylative fluorinations, 2 vinylations, 3 alkynylations, 4 hydrodecarboxylation, 5 hydroxylation, 6 conjugate additions 7 and radical−radical coupling reactions. 8 Despite these seminal studies, few photocatalytic decarboxylative oxidations have been reported (Figure 1).…”