posted on 2019-12-16, 12:42authored byGamze Tanriver, Dylan Dagoneau, Ulfet Karadeniz, Amandine Kolleth, Alexandre Lumbroso, Sarah Sulzer-Mossé, Alain De Mesmaeker, Saron Catak
A predictive computational study was conducted in order
to assess
the efficiency of electrocyclization reactions of keteniminium salts,
in an effort to form a variety of heterocyclic systems, namely, 3-amino(benzo)thiophenes,
3-amino(benzo)furans, 3-aminopyrroles, as well as 3-aminoindoles.
A density functional theory (DFT) approach was utilized and the effect
of heteroatoms (NMe, O, S) was thoroughly investigated by means of
population analysis, QTAIM, NICS, ACID, and local reactivity descriptors
(Parr and Fukui functions). The electrocyclization of enamines leading
to 3-aminopyrroles was shown to be both kinetically and thermodynamically
most favorable. Moreover, the pericyclic nature of the electrocyclizations
was confirmed using FMO, QTAIM, NICS, and ACID methods. Additionally,
substituent effects were investigated in order to give further insight
on the reactivity of heteroatom containing keteniminium systems toward
electrocyclization reactions. Finally, computational predictions were
experimentally confirmed for a selection of keteniminium systems.