Isocyanates are important and versatile reagents for both fine and large-scale organic synthesis. The main use of isocyanates is the production of widely used polyurethanes (PU) -indispensable component in the manufacturing process of protective coatings, adhesives, dyes, sealants, various wear-resistant materials, biomaterials, etc. In addition, methyl isocyanate is an important intermediate in the synthesis of carbamate pesticides. The large-scale manufacture of isocyanate is usually based on the reaction of amines with toxic phosgene (Figure , reaction A). On a laboratory scale, isocyanates are usually prepared by one of the rearrangement reactions -e.g., Lossen rearrangement (Figure , reaction B), Hofmann rearrangement (Figure , reaction C), and Curtius rearrangement (Figure , reaction D). At the same time, alternative approaches toward isocyanates have also been described in the literature. One such reaction is the thermal or catalyzed rearrangement of nitrile oxides. Ar C N + O - Ref. found in the initializing post in the VK social network. Possible pathways of rearrangement between isomeric nitrile oxides (R-C ---N + -O -), cyanates (R-O-C ---N), and isocyanates (R-N--C --O) have captivated the attention of chemists for over a century. Since the development of computational chemistry, numerous studies have aimed to explain the nitrile-oxide-to-isocyanate isomerization; however, usually, the objects were "spherical cows molecules in a vacuum." Thus, chemically unreliable barriers exceeding 50 and sometimes even 80 kcal/mol were obtained. In 1977, fascinatingly illogical isomerization from nitrile oxides to isocyanate under relatively mild conditions was demonstrated, but remained almost unnoticed (see Figure ). Authors speculated that the reaction proceeds through the 1,3-dipolar cycloaddition (Huisgen reaction), and thus isomerization is an oxygen exchange, with SO 2 playing an atypical role of a catalyst. This assumption also bridges the suggested mechanism with a reaction between nitrile oxides and sulfinylamines that results in carbodiimides. However, such a chemical transformation caused some confusion when one of our research team members came across a post on the VK social network.[15] Thus, an idea to create a crowd-effort project to study this rearrangement pathway came out. The result of this was the creation of self-organized collaboration, initiated with the corresponding post in the VK social network. In the current study, we present a detailed state-of-the-art in silico mechanistic investigation of the reaction mechanism of SO 2 -catalyzed conversion of phenylnitrile oxide into phenyl isocyanate. Based on the established reaction mechanism, we conduct a theoretical screening of other potential inorganic and organic catalysts. In the final part of the study, we also provide a screening of other possible substrates and their influence on the reaction's kinetics.