For unsymmetrical alkynes, trimethyl(phenylethynyl)silane and 1-phenyl-1-hexyne were tested and high yields along with high regioselectivity were obtained (27 and 28). The excellent regioselectivity can be explained by the stability of Fe-C bond at the α-styrenyl position (intermediate II in Figure ), πconjugation, as well as the steric effects illustrated in the inset figure. TIPS-protected phenylacetylene failed because of the large steric hindrance (29). Leveraging this regioselectivity, a double cyclization of 5 1 with 1,4-bis((trimethylsilyl)ethynyl)benzene provided a phenylene-linked conjugated structure in 61% yield as a pure regioisomer (30). The TMS substituents can function as a synthetic handle for further derivatization and annulation. The access to two π-extended structures from chromeno[3,2-c]xanthene-5,8-dione (31 and 32) was also achieved via a double cyclization. These molecules with an extended psystem and a donor-acceptor structure are worth exploring further to investigate their optoelectronic and 10 charge transport properties for potential applications in electronic materials.