Synthesis, Reactivity and Antimicrobial Activity of a Series of 2-Arylamino-1,3-selenazoles

A series of 2-arylamino-1,3-selenazoles was synthesized and their reactivity was studied. The 2-arylamino-1,3-selenazoles and their reaction products were characterized by various spectroscopic methods and X-ray diffraction. In addition, the antimicrobial activity of the 2-arylamino-1,3-selenazoles in a panel of seven bacteria and fungi was examined.

Isoselenocyanates: Synthesis and Their Use for Preparing Selenium-Based Heterocycles

Isoselenocyanates (ISCs) are a class of organoselenium compounds that have been recognized as potential chemotherapeutic and chemopreventative agents against cancer(s) and infectious diseases. ISC compounds are chemically analogous to their isosteric relatives, isothiocyanates (ITCs); however, they possess increased biological activity, such as enhanced cytotoxicity against cancer cells. ISCs not only serve as significant products, but also as precursors and essential intermediates for a variety of organoselenium compounds, such as selenium-containing heterocycles, which are biologically active. While syntheses of ISCs have become less difficult to accomplish, the syntheses of selenium-containing heterocycles are often difficult due to the use of highly toxic selenium reagents. Because of this, ISCs can serve as versatile reagents for the preparation of these heterocycles. In this review, the classical and recent syntheses of ISCs will be discussed, along with notable and recent synthetic work employing ISCs to access novel selenium-containing heterocycles.

1 Introduction

1.1 Selenium and Health

2 Isoselenocyanates

2.1 Preparation of Isoselenocyanates

3 Selenium-Containing Heterocycles

3.1 Notable Synthetic Work

3.2 Recent Synthetic Work

3.2.1 Synthesis of N-(3-Methyl-4-phenyl-3H-selenazol-2-ylidene)benzamide­ Derivatives

3.2.2 Synthesis and X-ray Studies of Diverse Selenourea Derivatives

3.2.3 Synthesis of Heteroarene-Fused [1,2,4]Thiadiazoles/Selenadiazoles via Iodine-Promoted [3+2] Oxidative Cyclization

3.2.4 2-Amino-1,3-selenazole Derivatives via Base-Promoted Multicomponent Reactions

4 Conclusion

One-Pot Four-Component Assembling for Selenoureas

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 was comprehensively achieved in one-pot with only the assistance of a base under mild conditions. Thirty-three new structures of unsymmetrical selenoureas including three chiral examples and eight cycloselenoureas were achieved. 1,1-Dimethyl-3-phenylselenourea II, which shows good fungicidal activity, was practically synthesized through this protocol in gram-scale. Isoselenocyanate was further confirmed as a key intermediate by control experiment.

Bis-Selenoureas for Anion Binding: A 1H NMR and Theoretical Study

The anion binding ability of a family of bis-selenoureas L1-L3 obtained by the reaction of 1,3-bis(aminomethyl)-benzene and phenylisoselenocyanate, p-methoxyphenylisoselenocyanate and naphtylisoselenocyanate, for L1, L2, and L3, respectively, has been tested and compared to that of previously described bis-urea analogues. Results suggest that the introduction of selenium leads to an increase in the acidity of the urea NH hydrogen atoms, and therefore to a stronger affinity (more than three-fold higher) towards anion species, in particular dihydrogen phosphate, in DMSO-d₆ . Theoretical calculations allowed for the optimization of the adducts receptors corroborating the experimental results.

Rational design and action mechanisms of chemically innovative organoselenium in cancer therapy

Organo-seleno compounds (org-Se) have been widely used in antitumor, antiviral, and antiinflammatory therapy; antioxidation and other biological fields. As such, they have made an important contribution to overcoming various kinds of diseases, and researchers are increasingly attracted to org-Se's synthesis and functional design. This review is mainly focused on the design and synthesis of various kinds of org-Se, followed by their anticancer mechanisms such as the mitochondria mediated pathway induced by ROS, death receptor mediated pathways involving p53 phosphorylation, and the activation of the AMPK pathway to promote apoptosis. Org-Se also serves as a sensitizer in chemotherapy and radiotherapy, and an antagonist against the cytotoxic effects induced by chemotherapeutic agents. Finally, we will summarize the development of cancer-targeted org-Se containing complexes, and nanotechnology-based org-Se for anticancer application. This review could provide information for the future design of chemically innovative org-Se with anticancer potential, and shed light on the discovery of nanomaterial-based pharmaceuticals to improve drug development and formation.