From an Insecticide to Plato's Universe—The Pagodane Route to Dodecahedranes: New Pathways and New Perspectives

TLDR: The original concept for the synthesis of pentagonal dodecahedranes by the conversion of structurally similar, high-energy pagodanes relied on catalytic dehydrocyclization as discussed by the authors.

Abstract: The original concept for the synthesis of pentagonal dodecahedranes by the conversion of structurally similar, high-energy [1111]pagodanes relied on catalytic dehydrocyclizations As a consequence, preparative limitations were preprogrammed With multiple functionalization of these pagodanes, alternative cyclization methods became viable These efficient processes allowed access to a multitude of pentagonal and nonpentagonal, carba- and heterocyclic dodecahedral skeletons with widely variable substitution patterns Such a roundabout route provided the (CH)20 basic framework with high efficiency, and long-lacking thermochemical data could be ascertained calorimetrically In spite of the unusually pronounced pyramidalization of their olefinic centers, singly and doubly unsaturated dodecahedranes with isolated CC bonds proved to be kinetically quite stable, but underwent dimerization on thermal activation Dodecahedranes with a higher degree of unsaturation (trienes–decaenes, C20 fullerene?) have been found so far only in the gas phase Higher fullerenes, including C60, have been identified by mass spectrometry after exposure of halogenated dodecahedranes and pagodanes to a 248-nm excimer laser Transannular electron delocalization has been verified for the “slender” pagodane/isopagodane and even for the “spherical” dodecahedrane cages