High-Yield Formation of Substituted Tetracyanobutadienes from Reaction of Ynamides with Tetracyanoethylene

The authors gratefully acknowledge Dr. L. Toupet from Institut de Physique de Rennes for solving X-ray structures, T. C. Nguyen for help in performing DFT calculations and Pr. A. Boucekkine for useful discussions.; International audience; A high-yielding sequence of [2+2] cycloaddition-retroelectrocyclization of ynamides with tetracyanoethylene (TCNE) is described. The reaction provided tetracyanobutadiene (TCBD) species, which were characterized by various techniques. DFT and TD-DFT calculations were also performed to complement experimental findings.