Is It Possible to Achieve Organic Superbases beyond the Basicity Limit Using Tetrahedrane Scaffolds?

Substituted tetrahedranes offer exceptional carbon bases with the gas‐phase proton affinities (PAs) up to 356 kcal mol −1 , due to the strain‐induced ring opening upon protonation. Additional tetrahedrane moieties exert a dramatic basicity amplification to PAs reaching 600 kcal mol −1 , being the strongest organic superbases reported, clearly surpassing the proposed limit of achievable basicities (Angew. Chem. Int. Ed. 2015, 54, 9262). However, because protonation/deprotonation of these compounds is not reversible, PAs of the opened‐cage isomers were calculated which were lower than the basiciy limit.