By Shaoguang Zhang
In this thesis, the writer introduces suggestions used to build quite a few kinds of N-heterocycles, according to the chemistry of zirconacycles and 2,6-diazasemibullvalenes. within the first half, the writer offers the advance of multi-component cyclization of a zirconacyclobutene-silacyclobutene fused compound, nitriles and unsaturated compounds. those reactions offer synthetically beneficial technique for numerous N-heterocycles akin to 3-acyl pyrrole, pyrrolo[3,2-d]pyridazine and dihydropyrroloazepine, that are all tricky to synthesize through different potential. The isolation and characterization of the major three-fused-ring Zr/Si-containing intermediates also are defined intimately. those effects convey that the zirconacyclobutene-silacyclobutene fused compound behaves as a “chemical transformer” upon remedy with a variety of substrates through the “coordination-induced skeleton rearrangement” mechanism. within the moment half, the writer demonstrates the synthesis and isolation of a sequence of 2,6-diazasemibullvalenes (NSBVs) from the response of 1,4-dilithio-1,3-dienes and nitriles, highlighting the numerous growth made for the 1st time during this paintings: (1) decision of X-ray crystal constitution of a substituted 2,6-diazasemibullvalene; (2) dimension of the activation barrier of its fast intramolecular aza-Cope rearrangement in resolution; (3) exploration of a number of response varieties of NSBV with different ring-expansion items and “bowl-shape” or “cage-shape” N-containing polycyclic skeletons; (4) demonstration of the localized constitution because the fundamental shape and the homoaromatic delocalized constitution as a minor part within the equilibrium utilizing theoretical research. according to well-founded effects, this paintings sheds new mild in this debatable topic.