Diselenides and Selenocyanates as Versatile Precursors for the Synthesis of Pharmaceutically Relevant Compounds

Copper-Catalyzed 1,5-Trifluoromethyl-thio(seleno)cyanation of 5-Hexenenitriles with an Intramolecular Cyano Migration

A copper-catalyzed remote 1,5-trifluoromethyl thio(seleno)cyanation of 5-hexenenitriles with an intramolecular cyano migration has been established, affording a variety of CF3/CN-containing thiocyanates and selenocyanates under mild conditions. The reaction features high chemo- and regioselectivities and illustrates potential value in synthetic chemistry.

Visible-light-promoted selenylation/cyclization of o-(1-alkynyl) benzoates to access seleno-substituted isocoumarins

A simple and efficient method to access 4-selenyl-isocoumarin derivatives through visible-light-promoted selenylation/cyclization of o-(1-alkynyl) benzoates has been developed. This transformation is performed under mild conditions and has the advantages of functional group tolerance and broad substrate scope.

Recent Progress in Synthetic and Biological Application of Diorganyl Diselenides

Diorganyl diselenides have emerged as privileged structures because they are easy to prepare, have distinct reactivity, and have broad biological activity. They have also been used in the synthesis of natural products as an electrophile in the organoselenylation of aromatic systems and peptides, reductions of alkenes, and nucleophilic substitution. This review summarizes the advancements in methods for the transformations promoted by diorganyl diselenides in the main functions of organic chemistry. Parallel, it will also describe the main findings on pharmacology and toxicology of diorganyl diselenides, emphasizing anti-inflammatory, hypoglycemic, chemotherapeutic, and antimicrobial activities. Therefore, an examination detailing the reactivity and biological characteristics of diorganyl diselenides provides valuable insights for academic researchers and industrial professionals.

Telescoping Synthesis of 4-Organyl-5-(organylselanyl)thiazol-2-amines Promoted by Ultrasound

In this work, we describe the synthesis of new 4-organyl-5-(organylselanyl)thiazol-2-amine hybrids through a one-pot two-step protocol. The transition metal-free method involves the use of ultrasound as an alternative energy source and Oxone® as oxidant. To obtain the products, a telescoping approach was used, in which 4-organylthiazol-2-amines were firstly prepared under ultrasonic irradiation, followed by the addition of diorganyl diselenides and Oxone®. Thus, 16 compounds were prepared, with yields ranging from 61 % to 98 %, using 2-bromoacetophenone derivatives and diorganyl diselenides as easily available starting materials.

Recent Advances in the Use of Diorganyl Diselenides as Versatile Catalysts

The importance of organoselenium compounds has been increasing in synthetic chemistry. These reagents are well-known as electrophiles and nucleophiles in many organic transformations, and in recent years, their functionality as catalysts has also been largely explored. The interest in organoselenium-based catalysts is due to their high efficacy, mild reaction conditions, strong functional compatibility, and great selectivity. Allied to organoselenium catalysts, the use of inorganic and organic oxidants that act by regenerating the catalytic species for the reaction pathway is common. Here, we provide a comprehensive review of the last five years of organic transformations promoted by diorganyl diselenide as a selenium-based catalyst. This report is divided into four sections: (1) cyclisation reactions, (2) addition reactions and oxidative functionalisation, (3) oxidation and reduction reactions, and (4) reactions involving phosphorus-containing starting materials.

To Cut the Mustard: Antimicrobial Activity of Selenocyanates on the Plate and in the Gas Phase

Organic selenocyanates (RSeCN) are among the most reactive and biologically active Se species, often exhibiting a pronounced cytotoxic activity against mammalian cells and microorganisms. Various aromatic selenocyanates have been synthesized and, similar to some of the most Reactive Sulfur Species (RSS), such as allicin, found to be active against a range of bacteria, including Escherichia coli, Pseudomonas syringae and Micrococcus luteus, and fungi, including Verticillium dahlia, Verticillium longisporum, Alternaria brassicicola, and Botrytis cinerea, even via the gas phase. The highest antimicrobial activity has been observed for benzyl selenocyanate, which inhibited the growth of all bacteria considerably, even at the lowest tested concentration of 50 µM. Notably, neither the analogues thiocyanate (BTC) nor isothiocyanate (BITC) show any of these activities, rendering this selenium motif rather special in activity and mode of action. Eventually, these findings advocate a range of potential applications of organic selenocyanates in medicine and agriculture.