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The chemistry of zirconacycles and 2,6-diazasemibullvalenes [electronic resource] : synthesis, structures, reactions, and applications in the synthesis of novel N-heterocycles / Shaoguang Zhang.

9783662450215 electronic book
3662450216 electronic book
9783662450208

Heidelberg : Springer, [2015]

English

1 online resource (xi, 173 pages) : illustrations (some color).

10.1007/978-3-662-45021-5 doi

QD411 .Z43 2015eb

547.05

In this thesis, the author introduces two strategies used to construct various types of N-heterocycles, based on the chemistry of zirconacycles and 2,6-diazasemibullvalenes. In the first part, the author presents the development of multi-component cyclization of a zirconacyclobutene-silacyclobutene fused compound, nitriles and unsaturated compounds. These reactions provide synthetically useful methodology for various N-heterocycles such as 3-acyl pyrrole, pyrrolo[3,2-d]pyridazine and dihydropyrroloazepine, which are all difficult to synthesize by other means. The isolation and characterization of the key three-fused-ring Zr/Si-containing intermediates are also described in detail. These results show that the zirconacyclobutene-silacyclobutene fused compound behaves as a ℓ́ℓchemical transformerℓ́ℓ upon treatment with various substrates via the ℓ́ℓcoordination-induced skeleton rearrangementℓ́ℓ mechanism. In the second part, the author demonstrates the synthesis and isolation of a series of 2,6-diazasemibullvalenes (NSBVs) from the reaction of 1,4-dilithio-1,3-dienes and nitriles, highlighting the significant progress made for the first time in this work: (1) determination of X-ray crystal structure of a substituted 2,6-diazasemibullvalene; (2) measurement of the activation barrier of its rapid intramolecular aza-Cope rearrangement in solution; (3) exploration of several reaction types of NSBV with diverse ring-expansion products and ℓ́ℓbowl-shapeℓ́ℓ or ℓ́ℓcage-shapeℓ́ℓ N-containing polycyclic skeletons; (4) demonstration of the localized structure as the predominant form and the homoaromatic delocalized structure as a minor component in the equilibrium using theoretical analysis. Based on well-founded results, this work sheds new light on this controversial topic.

"Doctoral thesis accepted by Peking University, Beijing, China."

Includes bibliographical references.

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Online resource; title from PDF title page (SpringerLink, viewed December 19, 2014).

Springer theses.

Print version: 9783662450208

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