Regioselective IED Diels-Alder Reaction of Bis-(4,6-dichloro-[1,3,5]triazin-2-yl)-diazene with Furan and Its Molecular Mechanism

The reaction of bis-(4,6-dichloro-[1,3,5]triazin-2-yl)-diazene with furan proceeds with the formation of inverse electron demand Diels-Alder product with a high yield. M06 2X/6 31G(d,p) calculations show thermodynamic instability of “normal” DA reaction product and predict its [3,3] sigmatropic rearrangement to the thermodynamically more favorable formal IEDDA reaction product. The obtained NMR spectra were in good agreement with GIAO calculations and were in accordance with DFT thermochemical data that confirmed the formation of the described product. IR and UV/Vis spectral data was also obtained and discussed.