semiconducting polymers. Regioregular oxazole-flanked thiophene, benzothiadiazole, naphthalene diimide (NDI), and thienopyrroledione (TPD) were successfully isolated via stannylation of oxazole and the Stille coupling of brominated core units (overall yields ranging from ca. 40 to 60%). From subsequent direct arylation polymerization, NDI/oxazole/TPD-containing regioisomeric polymers were obtained with