Scalable Synthesis of Naphthothiophene-based D-π-D Extended Oligomers through Cascade Direct Arylation Processes

Abstract

The synthesis of two novel π-extended oligomers, incorporating naphtho[1,2-b]thiophene-4-carboxylate 2-octyldodecyl esters as end-capping moieties, and two different conjugated core fragments, has been achieved through a cascade sequence of sustainable organic reactions. Benzo[c][1,2,5]thiadiazole and 2-octyldodecyl benzo[1,2-b:6,5-b′]dithiophene-4-carboxylate have been used, respectively, as electron-poor and electro-rich π-conjugated cores. In the latter case, a sequence of nine aromatic rings in a fully conjugated structure is achieved with a high yielding, sustainable cascade approach. The optoelectronic properties of both oligomers are reported.