Spirocyclic Diaminocarbenes: Synthesis, Coordination Chemistry, and Investigation of Their Dimerization Behavior

Autor:	Roland Fröhlich, Martin Paas, F. Ekkehardt Hahn, Duc Le Van
Rok vydání:	2005
Předmět:	chemistry.chemical_classification Stereochemistry Organic Chemistry chemistry.chemical_element General Chemistry Carbon-13 NMR Ring (chemistry) Catalysis Coordination complex chemistry.chemical_compound chemistry Yield (chemistry) Molecule Lithium Spectroscopy Carbene
Zdroj:	Chemistry - A European Journal. 11:5080-5085
ISSN:	1521-3765 0947-6539
DOI:	10.1002/chem.200500306
Popis:	Nonaromatic, "saturated", spirocyclic N-heterocyclic diaminocarbenes 11 can be obtained from spirocyclic imidazolidin-2-thiones 10 by reductive desulfurization with potassium. The unsymmetrically N,N'-substituted spirocyclic imidazolidin-2-thiones were obtained by reaction of ketimines 9 with lithium N-butyl-N-lithiomethyldithiocarbamate (6). 1 3 C NMR spectroscopy revealed that the unsymmetrically N,N'-substituted spirocyclic imidazolidin-2-ylidene 11a undergoes a slow, acid-catalyzed dimerization to give the enetetramine lla=lla, which exists in two isomeric forms (syn and anti). This reaction is reversible under special circumstances. Carbenes of type 11 react with [W(CO) 6 ] to yield air-stable carbene complexes of type [W(11)(CO) 5 ] (14). The molecular structures of two derivatives 14a and 14b were established by X-ray crystallography and show clear distortion of the five-membered N-heterocyclic ring, caused by the spirocyclic molecular structure of the carbene ligands of type 11.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8eda8785deda3334374cfd52cb1aad5e https://doi.org/10.1002/chem.200500306 Zobrazit plný text záznamu Plný text