Organoselenium Chemistry: after 200 years the "Gold Rush" is still open

For a long time, the main biological activity of selenium derivatives was supposed to be connected to their toxicity and some exotic theories correlated historical events to the selenium poisoning. In 1285, Marco Polo, crossing the Shanxi Province of Western China, observed an unknown intoxication of the animals on his ships (loss of hair) that later was supposed to be due to selenosis and in 1860, a US Army surgeon documented the first selenium poisoning in livestock, suggesting a fascinating theory that the horse illness that slowed General Custer's Cavalry relief may have been due to selenium intoxication. Even if nowadays, several studies have confirmed that some disorders in animals and humans are consequence of selenium bioaccumulation it is also clear that selenium is fundamental for life having the role of essential micronutrient in mammals. As direct consequence of these prejudices the research in the field was particularly slow in the past and relegated to a small number of group in the world. Only recently the knowledge acquired in 200 years of basic research are finding applications in understanding of biological models involving selenoproteins, developing of new drugs, new functionalized materials and new catalytic protocols for green chemistry. This manuscript aims to be a celebrative tribute to the 200^th  "selenium birthday" presenting an overview of the contribute of our group in different field of this research, ranging from the development of new reagents for green chemistry and catalysis to the design and synthesis of novel molecules as anti-HIV and antimicrobial agents. We are strongly convinced that in the next future we can expect important discoveries from a research that produce thousand of new publications every year. Here we'll trace also where we are going to collecting some selected results recently obtained and presented by s number of our young students at 6th Workshop of the SeSRedCat Network in Wroclaw Poland 21-23 September 2017)