DFT study of double 1,3-dipolar cycloaddition of nitrilimines with allenoates

The double 1,3-dipolar cycloaddition reaction between nitrilimine and allenoate, experimentally investigated by Guo and co-workers, was theoretically studied at the B3LYP/6-311G** and wB97XD/6-311G** computational levels in both gas phase and dichloromethane solution. The results indicated that the formation of the experimentally reported product is clearly explained by the analysis of the calculated Fukui function reactivity indices as well as transition states studies. Frontier molecular orbitals analysis showed that the HOMO orbital of nitrilimine as donor is also the frontier effective-for-reaction molecular orbital(FERMO). Finally, on the basis of the Wiberg bond indexes and AIM analysis, it was found that all of the reactive channels proceed through an asynchronous concerted mechanism. [GRAPHICS]