The Huisgen reaction, also known as 1,3-dipolar cycloaddition, has become an indispensable tool in modern organic chemistry. This type of reactions is now widely employed for the preparation of heterocycles and is also involved in many applications for the synthesis of natural products and biologically active compounds. The success of cycloaddition reactions relies on their potential to provide access to four-, five-, and six-membered rings with excellent stereocontrol and yield. For instance, the Diels–Alder reaction is a [4+2] cycloaddition that yields a functionalized six-membered ring product. Generally, it is well known that cycloaddition reactions are commonly characterized by a concerted mechanism, and thus, the atoms on the dienophile or the diene maintain their orientation in the product. Additionally, 1,3-dipolar reactions have also been theoretically investigated over the last few decades by theoretical chemists in order to explain their kinetics mechanism and study their yields, regioselectivity, and stereochemistry with available theories and approaches. The analogy to the electronically equivalent Diels–Alder reactions was evident. Back in 1960, the concerted reaction mechanism of cycloadditions was proven by both experiment and theory, and it was found to be a good explanation for most [3+2] cycloadditions. In this study, the most popular density functional theory (DFT) B3LYP method was used to characterize two 1,3-dipolar cycloaddition reactions, i.e., the regioselectivity using conceptual DFT, such as Fukui and Parr functions, and the exploration of reaction mechanisms via the elaboration of the energetic profile.