6533b82dfe1ef96bd1291bc1

RESEARCH PRODUCT

The domino reaction between 4,6-dinitrobenzofuroxan and cyclopentadiene. Insights on the nature of the molecular mechanism

subject

description

Abstract The molecular mechanism of the domino reaction between 4,6-dinitrobenzofuroxan, 1 , and cyclopentadiene, Cp, to give the adduct 11 is examined through density functional theory (DFT) calculations at B3LYP/6-31G* level. This domino reaction comprises two consecutive formally [4+2] cycloadditions. The first one is a two-center addition initialized by the nucleophilic attack of Cp to the more electrophilic center of 1 . The subsequent cyclization can take place along two competitive channels associated to the formation of a second C–C bond yielding the formally [2+4] cycloadduct 9 , or a C–O bond yielding the formally [4+2] cycloadduct 10 . The second cycloaddition is a stepwise process that is initialized by the nucleophilic attack of a second molecule of Cp to 10 . The energetic results are in agreement with the experiments allowing to explain the formation of the final domino adduct 11 . Inclusion of solvent effects, via a polarizable continuum model, decreases the activation energies of these polar processes. A DFT analysis of the indexes of reactivity provides a sound explanation on the reactivity of 1 on this domino reaction.