RESUMO
An interesting molecular architecture, butterflyene, resembling the shape of a butterfly has been synthesized via a sequence of cyclocondensation, benzylic oxidation, McMurry coupling and Diels-Alder reaction (DAR), successively. The DAR of the tetrasubstituted double bond of a bicyclopentylidene moiety with various dienes has been performed to prepare the analogues of butterflyene. DFT calculations have also been used to analyze the structural optimization and reaction energies.
RESUMO
Pesticide deposits post-treatment and before diffusing inside the plants are exposed to sunlight. Many of them degrade into a variety of photoproducts that may be harmful to living beings through accidental ingestion. The addition of ultraviolet light absorbers to the pesticide formulations is an attractive strategy to prevent photodegradation of the pesticides. Water-soluble quaternary ammonium ultraviolet light absorbers (QAUVAs) were synthesized from 2,4-dihydroxy benzophenones (BP-1) and their structures were confirmed by 1H NMR, 13C NMR, UV, and FTIR. A cost-saving approach for the photoprotection of disulfoton insecticide using these QAUVAs is presented. All the four QAUVAs exhibit excellent UV screening effect. The insecticide disulfoton was recovered in much higher amounts (22.27 ~ 25.64% higher than control) when it was irradiated in the presence of QAUVAs in comparison with the amount of recovery of pesticide exposed in absence of them.
RESUMO
Dodecahydrotriphenylene, a higher homologue of trindane chemoselectively undergoes unidirectional benzylic sp3 C-H oxidation and the central benzene ring remains intact unlike that in trindane under similar reaction conditions. RuO4 which generally attacks sp2 C-H to form oxidative products is found to give benzylic ketones via sp3 C-H oxidation. Density functional theory (DFT) calculations have also been performed to analyse the potential energy, energy barrier and HOMO-LUMO energy gap of the products.
