Ríos-Gutiérrez, MarDomingo, Luis R.Pérez, Patricia2023-08-222023-08-222015RSC Advances Volume 5, Issue 103, Pages 84797 - 8480920152046-2069https://repositorio.unab.cl/xmlui/handle/ria/52733Indexación: ScopusThe high reactivity of carbonyl compounds towards the carbenoid intermediate cis-IN, generated in situ by the addition of methyl isocyanide to dimethyl acetylenedicarboxylate (DMAD), has been investigated at the MPWB1K/6-311G(d,p) computational level by using Molecular Electron-Density Theory (MEDT). This multicomponent (MC) reaction is a domino process that comprises two sequential reactions: (i) the formation of a nucleophilic carbenoid intermediate trans-IN; and (ii) the nucleophilic attack of cis-IN on the carbonyl compound, resulting in the formation of the final 2-iminofuran derivative. The present MEDT study establishes that the high nucleophilic character and the electronic structure of the carbenoid intermediate, cis-IN, together with the specific approach mode of the carbonyl CO double bond during the nucleophilic attack of the sp2 hybridised carbenoid C4 center of cis-IN on the carbonyl C5 carbon of acetone, enables the formation of the C4-C5 single bond with a very low activation enthalpy, 3.3 kcal mol-1, without any external electrophilic activation of the carbonyl group, and the subsequent ring closure through the downhill formation of the C-O single bond. The Bonding Evolution Theory (BET) study for the formation of the 2-iminofuran allows characterisation of the mechanism as a [2n + 2n] cycloaddition, ruling out the proposed 1,3-dipolar cycloaddition mechanism. © The Royal Society of Chemistry 2015.enArtículoAtribución-NoComercial 4.0 Internacional (CC BY-NC 4.0)10.1039/c5ra15662a