The invention relates to a process for coupling thiophene or selenophene compounds, in particular for preparing conjugated thiophene or selenophene polymers with high molecular weight and high regioregularity, and to novel polymers prepared by this process. The invention further relates to the use of the novel polymers as semiconductors or charge transport materials in optical, electrooptical or electronic devices including field effect transistors (FETs), thin film transistors (TFT), electroluminescent, photovoltaic and sensor devices. The invention further relates to FETs and other semiconducting components or materials comprising the novel polymers.