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Hossein Reza Darabi Shabnam Mohandessi Yadollah Balavar Mojtaba Mirhosseini Moghaddam Kioumars Aghapoor Farshid Mohsenzadeh Abbas Ali Nourinia 《Environmental Chemistry Letters》2011,9(4):519-524
Pre-harvest sprouting refers to the precocious germination of the grain in the spike prior to harvest as a result of moist
weather conditions at harvest time. From the agricultural viewpoint, it is necessary to impose an exogenous dormancy to wheat
seeds in order to improve the resistance of seed to pre-harvest sprouting. In this regard, we found that clove bud essential
oil is a strong inhibitor for wheat seed germination. The extract obtained from clove bud by supercritical fluid extraction
using CO2 as solvent minimized the number of extracts to two compounds, eugenol and eugenyl acetate. Eugenol, as the main constituent
of the oil, was responsible for its strong inhibitory activity in wheat seeds. The aqueous solution of clove bud oil was submitted
to germination assay at various concentrations from 50 to 400 mg/L. Complete inhibition of seed germination was recorded when
the concentration was 400 mg/L. Roots and sprouts have similar sensitivity to inhibitory effect. In an empirical study, the
synergistic cooperation of eugenol and eugenyl acetate from clove bud oil in the inhibition of seed germination was found
to be a 1:1 ratio. The clove bud essential oil is widely available and will broaden the horizon of applications for natural
and safe inhibitors in the fields. 相似文献
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Aghapoor Kioumars Mohsenzadeh Farshid Sayahi Hani Rastgar Saeed Darabi Hossein Reza 《Environmental Chemistry Letters》2018,16(3):1109-1116
Environmental Chemistry Letters - The replacement of hazardous solvents by greener alternatives is a major goal in green chemistry. Benzimidazol-2-ones are heterocycles exhibiting a wide range of... 相似文献
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Hossein Reza Darabi Mohammad Reza Poorheravi Kioumars Aghapoor Asyeh Mirzaee Farshid Mohsenzadeh Nazafarin Asadollahnejad Hossein Taherzadeh Yadollah Balavar 《Environmental Chemistry Letters》2012,10(1):5-12
Heterogeneous catalysts are used for control of environmental pollution. Heterogeneous catalysts are easily separated from
the reaction mixture, thus allowing their recovery and re-use. There is a need for catalysts that are efficient under mild
conditions. Here, we show that silica-supported antimony(III) chloride (SbCl3/SiO2) acts as a highly efficient heterogeneous Lewis acid catalyst for the Paal–Knorr pyrrole synthesis at room temperature. We
found that condensation of hexane-2,5-dione with aromatic and aliphatic primary amines in hexane using SbCl3/SiO2 with 7.6 wt% SbCl3 was the best reaction condition. The silica support facilitated the workup of the reaction mixture and provided a reusable
catalyst at least for 7 runs without significant loss in activity. Indeed, the yield was 98% for the first run and 84% for
the 7th run. We conclude that low catalyst loading, operational simplicity, practicability and applicability to various substrates
make this reaction an interesting alternative to previously applied procedures. From the environmental standpoint, this eco-friendly
catalyst is stable, highly active, easy to prepare and handle. 相似文献
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Hossein Reza Darabi Kioumars Aghapoor Abbas Darestani Farahani Farshid Mohsenzadeh 《Environmental Chemistry Letters》2012,10(4):369-375
This investigation discloses a greener reaction to prepare pyrrole derivatives. Metal-free catalysts are greener alternatives to existing metal catalysts in synthetic organic chemistry. Indeed, transition metals are often costly and toxic. They may be found as traces in health reaction products such as pharmaceuticals. Alternatively small organic molecules termed “organocatalysts” allow the synthesis of valuable products without traces of toxic metals. Here, we show for the first time the use of vitamin B1 as new organocatalyst for the Paal–Knorr pyrrole synthesis under ambient conditions. Reaction conditions were optimized for the reaction of hexane-2,5-dione with 4-methoxyaniline. Ethanol was the most effective solvent. The conversion was quantitative using vitamin B1, by comparison with a low yield of 30?% without catalysis. The best conditions were performed in ethanol with 5?mol % of vitamin B1 during 1?h. This reaction was tested using various aromatic amines. To conclude the use of vitamin B1 for the Paal–Knorr pyrrole, cyclocondensation has mild reaction conditions, is simple to perform, and gives moderate to excellent yields. It is therefore a promising reaction for the preparation of various pyrrole derivatives. 相似文献
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