Synthesis and Structure of Digerma‐ and Distannacyclobutenes

Abstract

The (crystalline) title compound 2 is the first distannacyclobutene. Other than the corresponding germanium compounds such as 1, 2 already dissociates reversibly into the starting compounds—cycloalkyne and stannanediyl—in solution at room temperature. This is apparently due to the fact that the energy of the CSn bond is markedly less than that of the CGe bond, and can no longer compensate the ring strain.