Perfluorobicyclo[2.2.0]hex-1(4)-ene as unique partner for Diels–Alder reactions with benzene: a density functional theory study

Abstract

The mechanism of the Diels–Alder reactions between perfluorobicyclo[2.2.0]hex-1(4)-ene (1a) and bicyclo[2.2.0]hex-1(4)-ene (1b) with benzene (2a) and naphthalene (2b) has been studied within the density functional theory at the MPWB1K/6-311G(d,p) level. The bonding pattern in these reactions is analyzed in the topology of the electron localization function within the bonding evolution theory perspective. The bonding electron density changes along the reaction paths reveal that the C–C bond formation takes place through a synchronous and non-concerted one-step mechanism and proceeds with a moderate activation energy. The reactivity order with 1a is 2a–2b. The reactions begin by the rupture of the double bond in the strained 1a-b molecules, and then two pseudoradical centers at the 1a-b fragments are created. Finally, at the same time, two new single bonds are formed in the cycloaddition products. The TSs proceed with high global electron density transfer providing a polar character at these reactions.

On the Question of the Formation of Nitro-Functionalized 2,4-Pyrazole Analogs on the Basis of Nitrylimine Molecular Systems and 3,3,3-Trichloro-1-Nitroprop-1-Ene

“…Within MCs, no new chemical bonds were formed. Similar-type intermediates have been identified recently regarding many bimolecular processes, such as 32CAs [32,[57][58][59], Diels-Alder reactions [54,60,61] and others [62][63][64]. Independent of the considered cycloaddition channel, the second reaction stage was a formation of the transition-state structure (TS) (Figure 2).…”

Understanding the Regioselectivity and the Molecular Mechanism of [3 + 2] Cycloaddition Reactions between Nitrous Oxide and Conjugated Nitroalkenes: A DFT Computational Study

“…For the exploration of the energetic profiles of the aforementioned processes, the wb97xd functional with the 6-311 + G(d) basis set was applied. A similar level of theory was very recently used for the exploration of different types of bimolecular processes, such as [3 + 2] cycloadditions [ 14 , 23 ] and [4 + 2] cycloadditions [ 24 , 25 ].…”

On the Question of Stepwise [4+2] Cycloaddition Reactions and Their Stereochemical Aspects

“…As is well known, arenes generally do not show the properties typical of alkenes or conjugated dienes. Sometimes, however, they can participate in [4+2] cycloaddition reactions as diene analogues [60]. For example, the reaction of anthracene 33 with 1,2-disubstituted nitroalkene 34 leads to the expected cycloadduct 35, and additionally, small amounts of the Michael adduct 37 [61] (Scheme 11).…”