2-tert-Butylfuran is a furan substituted at the 2-position with a tert-butyl group. This t-butyl substitution blocks the 2-position, allowing a quantitative functionalization of 2-tert-Butylfuran at the 5-position. A report describes using 2-tert-Butylfuran and other 2-alkyl furans to cap growing polyisobutenyl diphenylcarbenium (PIB+) polymers in the presence of TiCl4.
