نتایج جستجو برای: phosphorus yields
تعداد نتایج: 136623 فیلتر نتایج به سال:
Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
The availability of carbon from rising atmospheric carbon dioxide levels and of nitrogen from various human-induced inputs to ecosystems is continuously increasing; however, these increases are not paralleled by a similar increase in phosphorus inputs. The inexorable change in the stoichiometry of carbon and nitrogen relative to phosphorus has no equivalent in Earth's history. Here we report th...
In order to study the effect of application of nitrogen, phosphorus and biologic fertilizers on yield and yield components of native bean, an experiment was conducted as factorial in randomized complete block design with three replications in Lahijan, northern Iran in 2013. Treatments consisted of chemical nitrogen fertilizer (0, 60 and 120 kg ha-1 urea), chemical phosphorus fertilizer (0, 40 a...
Although, over the years, considerable interest has been shown in the transformation of aldoximes to nitriles, surprisingly few attempts have been made in utilizing derivatives of phosphorus for this purpose [1-7]. Best results were achieved using aromatic aldoximes, and only seldom were aliphatic aldoximes utilized, affording nitriles in only moderate yields. Recently [8], we reported a novel ...
The chemical synthesis of DNA and RNA is universally carried out using nucleoside phosphoramidites or H-phosphonates as synthons. This review focuses on the phosphorus chemistry behind these synthons and how it has been developed to generate procedures whereby yields per condensation approach 100% with very few side products. Additionally the synthesis and properties of certain DNA and RNA anal...
stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. these phosphoranes undergo smooth intramolecular wittig reaction followedby an electrocyclic ring opening to produce dialkyl (e)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1h-imidazol-4-yl)fum...
The reactions of cyclopropenones with nucleophiles (H2O or methanol) could be catalyzed by nitrogen-containing Lewis bases or phosphorus-containing Lewis bases, affording the corresponding mono- or multi-substituted allenic esters in moderate to excellent yields.
in order to investigate the effect of consumption of nitrogen and phosphorus fertilizers on harvest indices and some important agronomic traits of triticale (triticosecale wittmack var. javaniloo), a factorial experiment based on the randomized complete block design with three replications was conducted in paddy field of rice research institute of iran (rasht) during 2010-2012 for two years. th...
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