1613331-31-9Relevant academic research and scientific papers
Unexpected formation of a [4]radialene and dendralenes by addition of tetracyanoethylene to a tetraaryl[5]cumulene
Januszewski, Johanna A.,Hampel, Frank,Neiss, Christian,Goerling, Andreas,Tykwinski, Rik R.
supporting information, p. 3743 - 3747 (2014/04/17)
The use of cumulenes in synthetic transformations offers the possibility to form structurally interesting and potentially useful conjugated molecules. The cycloaddition reaction of a tetraaryl[5]cumulene with the electron-deficient olefin tetracyanoethylene affords unusual products, including functionalized dendralenes and alkylidene cyclobutanes, as well as a symmetric [4]radialene that shows unique solvatochromism, with λmax values approaching the near-IR region. These carbon-rich products have been investigated spectroscopically and by X-ray crystallographic analysis (five structures). The cycloaddition reaction sequence has also been explored by mechanistic and theoretical studies. The obtained results clearly demonstrate the potential of [5]cumulenes to serve as precursors for unprecedented conjugated structures. Unusual structures and interesting electronic properties characterize the cyclic products from the reaction of TCNE with tetraaryl[5]cumulene. Mechanistic investigations, aided by DFT calculations, outline a likely pathway to the observed products. The addition of MeOH, EtOH, and Br2 to various intermediates leads to the interesting dendralene compounds.
