Fukushima, Kazuaki published the artcileNatural bond orbital analysis of pericyclic and pseudopericyclic 1,5-electrocyclizations of conjugated nitrileimines, Synthetic Route of 63598-71-0, the publication is Bulletin of the Chemical Society of Japan (2004), 77(9), 1671-1679, database is CAplus.
Ab initio and DFT studies have revealed that there are three mechanisms in 1,5-electrocyclizations of conjugated nitrileimines. The first one is a pericyclic 1,5-electrocyclization of vinyl or (Z)-imino nitrileimine. Interactions between π-orbitals at C1 and X5 lead to formation of σC1-X5 bonds. The second one is a typical pseudopericyclic 1,5-electrocyclization of formyl nitrileimine. Nucleophilic interaction of lone pair electrons at O5 to π*C1-N2(h) leads to formation of a σC1-O5 bond. The natural bond orbital (NBO) anal. for the reaction has shown that there are two disconnections of orbital interactions at C1 and O5 at the transition state because of the orthogonal array of the forming σC1-O5 bond and the other π-orbitals. The third one is an incomplete pseudopericyclic 1,5-electrocyclization of (E)-imino nitrileimine. Nucleophilic interactions of lone pair electrons at N5 to π*C1-N2(h) and π*C1-N2(v) lead to formation of a σC1-N5 bond. There is a single disconnection of orbital interactions at N5 at the transition state, because the forming σC1-N5 bond and the other π-orbitals are orthogonal at N5 but not at C1, owing to twisting in the nitrileimine moiety.
Bulletin of the Chemical Society of Japan published new progress about 63598-71-0. 63598-71-0 belongs to triazoles, auxiliary class Triazole, name is 4H-1,2,4-Triazole, and the molecular formula is C2H3N3, Synthetic Route of 63598-71-0.
Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics