A regio- and stereoselective intramolecular direct aldol reaction of 2,7-diketones derived from carbohydrates has been developed to construct cycloalkanones , which were dehydrated to obtain heavily oxygenated cycloalkenones .

The practical application of most the UV-based advanced oxidation/reduction technologies (AOTs) is still limited because poor selectivity reactive species in AOTs and inner filter effects caused by complicated components water. Recently, new photochemical techniques based on low molecular weight diketones have attracted much attention higher stronger anti-interference ability. Thi...

This study presents our view of unconventional and conventional intramolecular hydrogen bonds (HBs) for some beta-diketones theoretically and experimentally. According to our results, the groups such as Phenyl and t-But in beta positions increase and CF3 group decrease IHB strength, respectively. For better understanding of the substitution effects, the compounds with similar and different subs...

A new variant of the NO(2)-to-CO transformation (the Nef reaction) that occurs at room temperature under neutral conditions is uncovered. After the conversion of secondary nitroalkanes to phenylsulfenylketimines, these thiooximes are hydrolyzed quantitatively in situ, in THF-H(2)O at pH 7, by addition of AuBr(3) (but not with other MX(n)!). Adducts arising from asymmetric nitro-Michael and nitr...

In order to study the effect of halogen bond on tautomerism in β-diketones solid-state, we have prepared a series cocrystals derived from an asymmetric β-diketone, benzoyl-4-pyridoylmethane (b4pm), as acceptor and perfluorinated iodobenzenes: iodopentaflourobenzene (ipfb), 1,2-, 1,3- 1,4-diiodotetraflorobenzene (12tfib, 13tfib 14tfib) 1,3,5-triiodo-2,4,6-trifluorobenzene (135titfb). All five ar...

The paper updates Isler's monograph of 1971 regarding the structures of naturally occurring carotenoids, their chemical reactions and their stereochemistry. Around ninety new structures are reported, including the new series of C30-carotenoids, enolized /3-diketones and several carotenoids with 2-hydroxy 3-rings. Progress in stereochemistry resulting in the configurational assignment of eleven ...

The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates. An interesting reaction is described wherein, with trifluoroacetic acid at lower temperature, it affords highly substituted 2-(trifluoromethyl)oxazoles. These flexible transformations proce...

The pressure hydrogenation capabilities of the iridium pincer complexes IrH2Cl[((i)Pr2PC2H4)2NH] (1) and IrH3[((i)Pr2PC2H4)2NH] (2) are described and compared to related results obtained previously in transfer hydrogenation. Complex 1 was shown to act as a convenient air-stable entry point to the active catalyst 2, in the presence of base and hydrogen gas. The catalysts are active in a range of...

Tetraarylpyrroles with a 1-azulenyl substituent were prepared by the reaction of 1-azulenyl ketones, which have various aryl-substituents at their α-position, with benzoin in the presence of ammonium acetate as a nitrogen source of the pyrrole ring. Optical property of the tetraarylpyrroles obtained by the reaction was clarified by UV/Vis spectroscopy and/or time-dependent density functional th...