Ethanol is shown to act as a hydrogenating agent for ynamides under palladium catalysis. This behavior is different from the normally expected reaction of ethanol addition to alkynes. The reaction ...shows stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources. The method was also extended to ynamines. Alternatively, the use of ethanol and ammonium formate as the hydrogenating source gives Z enamides. The role of ethanol in hydrogenation was demonstrated by means deuterium labeling experiment.
One for the road: Ethanol acts as a hydrogenating agent for ynamides under palladium catalysis. This behavior is different from the normally expected addition of ethanol to alkynes. The reactions show stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources, and the method was also extended to ynamines. Alternatively, the use of ethanol/ammonium formate as the hydrogenating source gives Z enamides.
The functionalization of materials for ultrasensitive detection of heavy metal ions (HMIs) in the environment is crucial. Herewith, we have functionalized inexpensive and environmentally friendly ...Fe3O4 nanoparticles with D-valine (Fe3O4–D–Val) by a simple co-precipitation synthetic approach characterized by XRD, FE-SEM, and FTIR spectroscopy. The Fe3O4–D–Val sensor was used for the ultrasensitive detection of Cd+2, Pb+2, and Cu+2 in water samples. This sensor shows a very low detection limit of 11.29, 4.59, and 20.07 nM for Cd+2, Pb+2, and Cu+2, respectively. The detection limits are much lower than the values suggested by the world health Organization. The real water samples were also analyzed using the developed sensor.
The radionuclide transfer between compartments is commonly described by transfer parameters representing the ratio of concentrations of an element in two compartments for equilibrium conditions. This ...is a comprehensive study on the soil-to-grass transfer factor (F
) and grass-to-cow milk transfer coefficient (F
) for stable strontium (Sr) for soil-grass (pasture)-cow (Bos taurus) milk environmental pathway under field conditions for a high rainfall tropical monsoonal climatic region of the Indian subcontinent. The study was conducted in the vicinity of the Kaiga nuclear power plant (NPP), situated ~ 58 km inland of the West Coast of the Indian subcontinent. A grass field was developed exclusively for this study, and two cows of the native breed were raised to graze on it. The soil, grass, and milk were analyzed to evaluate the F
and the F
values for the stable Sr. For comparison, several pasture lands and the cows raised by the villagers and a dairy farm were also studied. The F
values were in the range 0.18-8.6, the geometric mean (GM) being 1.8. The correlations of F
values with a range of physicochemical parameters are presented. The GM values for F
were 2.2 × 10
d L
and 7.2 × 10
d L
for the two cows raised for this study, 2.6 × 10
d L
for those raised by the villagers, and 4.2 × 10
d L
for the dairy farm. The site-specific F
value for the region was determined as 3.2 × 10
d L
. The concentration ratio (CR), defined as the ratio of Sr concentration in milk to that in feed under equilibrium conditions, exhibited less variability (1.8 × 10
-5.4 × 10
) among the three categories of cows.
•MCDM methods: AHP and TOPSIS.•AHP the decision-maker.•TOPSIS is stock to an ideal solution.
Building an ideal stock portfolio is a difficult and important undertaking in the world of financial ...decision-making. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) technique and the Randomised Weighted Fuzzy Analytic Hierarchy Process (AHP) are combined in this research to create a powerful model for selecting the best stocks for a portfolio. To improve the portfolio's robustness under various market scenarios, our model also incorporates sensitivity analysis. Given the inherent uncertainty in financial markets, the suggested approach starts by using modified fuzzy AHP based on introducing the randomized weights and the novel normalization to get expert views and assign suitable weights to the underlying selection criteria. Based on the established criteria and associated fuzzy scores, the TOPSIS approach is then used to rank and choose the best stocks. Our model also includes sensitivity analysis to evaluate the performance of the portfolio under various market conditions. Extensive empirical tests are performed utilizing historical stock market data to assess the effectiveness of our strategy. The outcomes show the suggested model's superiority in building stock portfolios that beat conventional approaches in terms of risk-adjusted returns.
A novel and efficient Cu-catalyzed one-pot regio- and stereospecific synthesis of benzo1,4,2dithiazine 1,1-dioxides and benzo1,4,2thiaselenazine 1,1-dioxides by cyclization of functionalized ...ynamides with elemental sulfur/selenium has been developed. Its generality is elegantly illustrated by extension to benzodithiazepines and benzothiaselenazepines. Involvement of water in the reaction is demonstrated by the incorporation of 2D at the olefinic site by using D2O in place of water. Selective oxidation at sulfur in benzo1,4,2dithiazine 1,1-dioxide by using mCPBA as the oxidizing agent is also described.
Recent research about Mitsunobo and other reactions is discussed. The Mitsunobu reaction is an important part in the synthesis of many organic transformations.
We present a measurement of R_{K^{*}}, the branching fraction ratio B(B→K^{*}μ^{+}μ^{-})/B(B→K^{*}e^{+}e^{-}), for both charged and neutral B mesons. The ratio for the charged case R_{K^{*+}} is the ...first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q^{2}. The analysis is based on a data sample of 711 fb^{-1}, containing 772×10^{6} BBover ¯ events, recorded at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The obtained results are consistent with standard model expectations.
Indole‐substituted purine nucleobases have been synthesized by Ru‐catalyzed oxidative annulation of 6‐anilinopurines with internal alkynes that involves CH activation. Unsymmetrical ...aryl(alkyl)alkynes led to high regioselectivity. The reaction was also successful with nucleosides by delivering unprotected indole‐substituted nucleosides. In the presence of RuCl2(p‐cymene)2 and copper(II) acetate hydrate Cu(OAc)2⋅H2O, in some cases, we have observed two‐fold CH activation products that exhibit fluorescence. A ruthenacycle intermediate was characterized by crystallography, which suggests that the N‐1 nitrogen atom of the purine acts as a directing group for the present transformation.
By introducing Syzygium samarangense (wax apple) as a novel reducing agent, we have synthesized reduced graphene oxide (r-GO) employing an eco-friendly method. We have adopted the modified Hummers' ...method to synthesize graphene oxide (GO), and the reduction has been accomplished entirely by a green route. The r-GO prepared using conventional reducing agents render hydrophobic property results agglomeration in solvents. By using Syzygium samarangense fruit extract (a mild green reducing agent), homogeneous dispersion achieved is a requisite for simple thin film deposition methods (sol-gel spin coating, dip coating and spray pyrolysis). The broad peak around 23.78° in the X-ray diffraction (XRD) pattern, increased ID/IG ratio (1.17) obtained from Raman spectroscopy, high carbon to oxygen ratio (4.8) from X-ray photoelectron spectroscopy (XPS), redshifted (286 nm) absorption peak in the Ultraviolet–visible spectra (UV–Vis) for few-layered r-GO reflect the reduction occurred in GO.
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•The Syzygium samarangense fruit extract used for GO reduction.•The few layered r-GO showed high carbon to oxygen ratio.•The possible reduction mechanism with Syzygium samarangense extract was proposed.•The band gap reduced from 4.06 eV (GO) to 3.18 eV (r-GO).
Lewis base dependent (3+3) annulations of β′/δ‐acetoxy allenoates with iminoindolines offer α‐carbolines with varying substituents depending on the base used as well as subtle changes in the reaction ...conditions. The phosphine‐catalyzed annulation of δ‐acetoxy allenoates with iminoindolines involves 6‐exo‐trig cyclization, tosyl anion elimination/trapping, and ethyl acetate elimination as key steps in delivering β‐H and γ‐tosyl containing α‐carbolines. An unobvious elimination (by Cα‐Cβ bond cleavage) of the −CH2CO2Et moiety is observed here. The same reactants under DBU catalysis offer α‐carbolines that retain −CH2CO2Et moiety but are devoid of −Ts group via 6‐exo‐dig cyclization. The reaction of β′‐acetoxy allenoate with iminoindolines is completely tertiary amine dependent; the use of DABCO affords tetrahydro‐α‐carbolines exclusively with excellent stereoselectivity while DBU offers substituted α‐carbolines that are distinct from those using DABCO. Several control experiments and HRMS studies have been done in support of a plausible reaction mechanism.
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