The construction of C–Chalcogen (S/Se/Te) bonds are becoming increasingly appreciated, due to the biological properties associated with the presence of these heteroatoms.¹  A large number of naturally existing biologically-active compounds have sulfur present in them.²  Historically, organoselenium/tellurium compounds were considered to be toxic toward human health and an environmental hazard. However, in the 1970s,^3,4  the discovery of the presence of the selenium atom in the structure of some proteins, caused increasing interest in the synthesis of organoselenium compounds. This also resulted in increased interest in the synthesis of organotellurium compounds and their biological application.⁴  Numerous reports demonstrate that several therapeutic activities are attributed to organochalcogen compounds such as their function as antioxidants, in several organs including the brain, prostate, stomach, colon, liver, lungs, kidneys, and skin, as apoptosis inducers, and chemopreventors.^4,5  Considering this, in the last decade, synthetic organochalcogen compounds have been vastly studied for numerous biological activities, such as an enzyme mimetic,^4,6  enzyme inhibition, anti-HIV,^4,5  antihypertensive activities, immune response, anticancer, anti-Alzheimer, and thyroid hormone production,⁷  among others (Figure 11.1).^4,5,8  Furthermore, a huge variety of organochalcogens have been successfully synthesized and screened as antimicrobial substances.^8f,9