Carbonate-promoted C-H carboxylation of electron-rich heteroarenes.

C-H carboxylation is an attractive transformation for both streamlining synthesis and valorizing CO. The high bond strength and very low acidity of most C-H bonds, as well as the low reactivity of CO, present fundamental challenges for this chemistry. Conventional methods for carboxylation of electron-rich heteroarenes require very strong organic bases to effect C-H deprotonation.

Polyamide monomers carbonate-promoted C-H carboxylation of furfurylamine.

Inedible biomass (lignocellulose) is a largely untapped resource for polymer production because it is synthetically challenging to convert to useful monomers. Here we describe streamlined syntheses of two polyamide monomers from furfurylamine, one of very few chemicals made industrially from lignocellulose. Using carbonate-promoted C-H carboxylation, furfurylamine is converted into a furan-containing amino acid and a tetrahydrofuran-containing bicyclic lactam in two and four steps, respectively.