Metabolically stable tert-butyl replacement

Article abstract of DOI:10.1021/ml400045j

Susceptibility to metabolism is a common issue with the tert-butyl group on compounds of medicinal interest. We demonstrate an approach of removing all the fully sp³ C-Hs from a tert-butyl group: replacing some C-Hs with C-Fs and increasing the s-character of the remaining C-Hs. This approach gave a trifluoromethylcyclopropyl group, which increased metabolic stability. Trifluoromethylcyclopropyl-containing analogues had consistently higher metabolic stability in vitro and in vivo compared to their tert-butyl-containing counterparts.