Synthesis and Properties of Azoles and Their Derivatives. Part 70. Nitroallylic Systems in [2 + 3] Cycloaddition Reactions with Nitrones: A DFT Computational Study

On the question of zwitterionic intermediates in 1,3-dipolar cycloadditions between hexafluoroacetone and sterically crowded diazocompounds

“…Hybrid functional B3LYP with the 6-31G(d) basis set included in the GAUSSIAN 09 package [13] was used. Recently published reports show, that the same theoretical level was used successfully for the mechanistic study of series one-step [14][15][16][17][18][19] and two-step [5,6,20] 1,3-dipolar cycloadditions as well as different reactions involving fluororganic compounds [21][22][23]. In addition, similar simulations using more advanced B3LYP/6-31+G(d), B3LYP/6-31G(d,p) as well as B3LYP/6-311G(d) theoretical levels were performed.…”

Competition between [2 + 1]- and [4 + 1]-cycloaddition mechanisms in reactions of conjugated nitroalkenes with dichlorocarbene in the light of a DFT computational study

“…On the other hand, five nitroalkenes (1ae) characterized by a different type of substitution were selected. All these nitrocompounds may be prepared with good yields [26], can exist as relatively stable compounds, and have been recently tested as components of other type cycloadditions (nitroethene 1a [14,16,27], 2-niroprop-1ene 1b [28], 1-chloro-1-nitroethene 1c [14,18,29], E-1nitroprop-1-ene 1d [28,30,31], E-2-chloro-1-nitroethene [31]). We hope that this study will help to further understand the nature of the title reactions and will be useful in organic synthesis.…”

A DFT computational study of the molecular mechanism of [3 + 2] cycloaddition reactions between nitroethene and benzonitrile N-oxides

“…Recently, we performed theoretical studies of a number of different cycloaddition processes involving conjugated nitroalkenes [24–30], and subsequently carried out experiments examining the reaction selectivity [27, 28, 30–32], activation parameters [33], and kinetic effects of the solvent and substituents [29, 34] for these processes. This comprehensive approach provided good insight into the key properties of the transition states involved.…”