Synthesis and characterization of pyridine- and thiophene-based platinacyclynes

Seven heterocyclic macrocycles, including the first platinacycles with pyridine and thiophene rings incorporated into the cyclyne system, are reported. Pt-acetylide cyclynes were assembled via tin transmetallation or amine-mediated oxidative addition with stoichiometric PtCl2(PEt3)2 and CuI. The organometallic cyclynes exhibited enhanced electronic properties compared to previously described platinabenzocyclynes.