Precisec ontrol of the selectivity in organic synthesis is importantt oa ccess the desired molecules. We demonstrate ar egiospecific annulation of unsymmetrically substituted 1,2-di(arylethynyl)benzened erivatives for ag eometrycontrolled synthesis of linear bispentalenes, which is one of the promisings tructures for materials cience.Ag old-catalyzed annulation of unsymmetrically substituted 1,2-di(arylethynyl)benzene could produce two isomeric pentalenes, but both electronic and steric effectso nt he aromatics at the terminal position of the alkyne prove to be crucial for the selectivity;e speciallyaregiospecific annulationw as achieved with sterically blockeds ubstituents;n amely,2 ,4,6-trimetylb enzene or 2,4-dimethyl benzene. This approache nables the geometrically controlled synthesis of linear bispentalenes from 1,2,4,5-tetraethynylbenzeneo r2 ,3,6,7-tetraethynylnaphthalene. Moreover,t he annulation of as eries of tetraynesw ith ad ifferent substitution pattern regioselectively provided the bispentalene scaffolds.Ac omputational study revealed that this is the result of ak inetic control induced by the bulky NHC ligands.