Bowl-to-Bowl Inversion Accelerated by the Introduction of Bulky 1,1,4,4-Tetramethylbutane-1,4-diyl Groups on Sumanene

Abstract

A variable-temperature 1H NMR study revealed that the bowl-to-bowl inversion of sumanene is accelerated by the introduction of bulky 1,1,4,4-tetramethylbutane-1,4-diyl groups on the peripheral aromatic ring. This is likely to be induced by a bowl flattening, as shown in the DFT-optimized structures.