Synthesis of Organoselenium Compounds with Elemental Selenium

Recent advances in organic synthesis applying elemental selenium

The one-pot multicomponent synthetic strategy of organoselenium compounds represents an alternative and robust protocol to the conventional multistep methods. During the last decade, a potential advance has been made in this domain. This review discusses the latest advances in the polymerization, metal, and metal-free one-pot multicomponent synthesis of organoselenium compounds.

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One-Pot Multicomponent Polymerization, Metal-, and Non-Metal-Catalyzed Synthesis of Organoselenium Compounds

Tetramethylammonium trifluoromethylselenate ([Me4N][SeCF3]) has been confirmed as an excellent precursor of selenofluorophosgene for amines in the preparation of selenocarbamoyl fluorides, selenoureas, and heterocycles under catalyst- and additive-free conditions. Reactions of [Me4N][SeCF3] with secondary amines at room temperature provided exclusively selenocarbamoyl fluorides in moderate to high yields, while the same reactions with primary amines afforded selenoureas in good yields. When [Me4N][SeCF3] was similarly mixed with amines containing adjacent amino, hydroxyl or thiol groups, five- and six-membered heterocycles were produced. The reaction featured simplicity, rapidness, high efficiency, a broad substrate scope, and good functional group tolerance, offering a convenient access to a variety of selenocarbonylated compounds, which were otherwise difficult to synthesize by other approaches.

Facile synthesis of selenocarbamyl fluorides, selenoureas and their derivatives with [Me4N][SeCF3]

Herein, we synthesized lanthanum (La)-doped sea sponge-shaped copper oxide (CuO) nanoparticles and wrapped them with novel O-, N- and S-rich (2Z,5Z)-3-acetyl-2-((3,4-dimethylphenyl)imino)-5-(2-oxoindolin-3-ylidene)thiazolidin-4-one (La@CuO-DMT). The shape and composition of the designed materials were confirmed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and Raman spectroscopy. The graphitic pencil electrode (GPE) fabricated using La@CuO-DMT showed excellent sensing efficacy against dopamine (DA) with good selectivity, reproducibility and ideal stability. The unique morphology and massive surface defects by La@CuO offer good accessibility to DA and enhance smooth and robust channeling of electrons at the electrode–electrolyte interface. Consequently, these properties resulted in improved reaction kinetics and robust DA oxidation with an amplified faradaic response. Meanwhile, O-, N-, and S-enriched carbon support, i.e. DMT, inhibited the leaching of electrode matrixes, resulting in a superior detection limit of 423 nm and an improved sensitivity of 13.9 μA μM−1 cm−2 in the linear range of 10 μM to 1500 μM. Additionally, the developed sensing interface was successfully employed to analyze DA from tear samples with excellent percentage recoveries. We expect that such engineered morphology-based nanoparticles with a O-, N-, and S-rich C support will facilitate the development of DA sensors for in vitro screening of rarely studied tear samples with good sensitivity and selectivity.

Functionalized thiazolidone-decorated lanthanum-doped copper oxide: novel heterocyclic sea sponge morphology for the efficient detection of dopamine

An efficient and practical method for the straightforward construction of unsymmetrical selenoureas and cycloselenoureas via the combination of selenium powder, chloroform, and two different amines...

One-Pot Four-Component Assembling for Selenoureas.

Metal nanoparticles stabilized by crystalline metal-organic frameworks (MOFs) are highly promising for green heterogeneous catalysis. In this work, in situ formed ultrafine Pd nanocatalysts with an average size of 3.14 nm have been successfully immobilized into the mesopores or defects of a water-stable indium-based MOF by the double-solvent method and subsequent reduction. Significantly, the obtained Pd@InOF-1 displays an obvious and satisfactory size-selective effect in the Suzuki-Miyaura coupling reaction between arylboronic acids and aryl bromides. On the basis of the synergistic effect, microporous InOF-1 nanorods afford a confined space for improving the selectivity of target products while Pd nanoparticles endow abundant active sites for catalysis. Herein, choosing the smallest size reactant with only one benzene ring gives the highest isolated yield of 90%, and if the size is larger, the yield is obviously reduced or even the target product could not be collected. Looking forward, this demonstrated study not only assembles a well-designed Pd@MOF composite with unique micro-nanostructures but also delivers an impressive option for cross-coupling reaction, which has implications for the further development of MOF hybrids for sustainable applications.

Size-Selective Suzuki-Miyaura Coupling Reaction over Ultrafine Pd Nanocatalysts in a Water-Stable Indium-Organic Framework.

An efficient glucose sensor thermally calcined from copper-organic coordination cages.

BACKGROUND
Medical insurance is considered to be closely related to individual health status, while their relationship are left to be clarified. This article aims to examine the relationship between medical insurance and the health status of residents in China.


METHODS
The data is from a nationally representative sample of CGSS2015, and the estimation methods of ordered logit model, generalised ordered logit model and instrumental variable (IV) were used.


RESULTS
Both public medical insurance (PMI) and commercial medical insurance (CMI) had a positive correlation with residents' self-assessed physical and mental health, while PMI was more statistically significant and substantively important than CMI. The basic results estimated with the generalised ordered logit model and IV model still remained robust. Further analysis found that medical insurance, whether public or commercial, had more or less weakened the importance of income to personal health, showing a substitute effect for income.


CONCLUSION
PMI has been proven to help promote the physical and mental health of residents and moderate the importance of residents' income to health. Besides, CMI also plays a beneficial supplementary role in promoting residents' health.

Linsha Wei

Papers

One-Pot Four-Component Assembling for Selenoureas.

Size-Selective Suzuki-Miyaura Coupling Reaction over Ultrafine Pd Nanocatalysts in a Water-Stable Indium-Organic Framework.

An efficient glucose sensor thermally calcined from copper-organic coordination cages.

Does medical insurance improve health? An empirical analysis from China.