The art of organic synthesis and reaction discovery relies on logic-guided thought processes that often involve hypovalent carbon reactive species and their corresponding stabilized equivalent forms. However, not all of the possible carbon reactive intermediates and their reactivity rules have attracted the same attention by the synthetic community. This is mainly because of the perception of the lack of synthetic utility and importantly, because of the challenges associated with controlling its extreme reactivity and lack of efficient sources. In this lecture, I will show how the catalytic generation of conceptually-novel radical carbenoids, carbyne equivalents, and metal-carbynoids enabled the discovery of new carbon reactivity towards C-H and C-C bonds. The metal or photocatalytic activation of tailored sources revealed new reactivity rules at carbon, useful in the creation of molecular complexity through unexplored disconnection approaches.