3,7-Diaza-bicyclo octan

The fluoraza reagents consist of two types of compounds one in which a fluorine atom is bound to the nitrogen atom of an amide or, more often, a sulfonamide and one in which a fluorine atom is bound to the nitrogen atom of a tertiary amine such as pyridine, quinuclidine, or triethylenediamine 1,4-diaza-bicyclo[2 2.2]octane. The positive charge on the nitrogen is counterbalanced by a non-nucleophilic anion such as triflate or tetrafluoroborate. 

Zur Demethylierung von quartaren Trimethylammonium-Salzen laBt sich auch 1,4-Diaza-bicyclo[2.2.2]octan in siedendem Ethanol oder Dimethylformamid verwenden. Aus den quartaren Ammonium-Salzen erhalt man auf diese Weise z. B. N,N-Dimethyl-anilin (92%) und 1-Dimethylamino-dodecan (68 %)2 ... 

The anancomeric l,3-di-tBu-l,3-diazacyclohexanes 113, 114 and the l,5-diaza-bicyclo[3.2.1]octanes 115-118 (cf. Scheme 42) were investigated to... 

On the other hand, TMEDA and Dabco (l,4-diaza-bicyclo[2.2.2]octane), both of which have an ethylenediamine unit and sterically bulky geometry, show time dependency of the spectral curves of intermediate saltex, indicating the instability of kinetically formed 1 1 ratio saltex and the thermodynamic transformation of the saltex to the 1 2 salt (Fig. 15). 

Cignarella, G Occelli, K Crisliani, G.. Pad-uamo, L., and Testa, H.. Bicyclic homologs of piperazine, VI. Synthesis and analgesic activity of 3-.substituted-8-propionyl-3,8-diaza-bicyclo[3.2.1 ]octanes. J. Med Chem., 6. 764. 1963. 

Diaza-bicyclo 3.3.0 octan 2,2-Dimethyl-4,4,8,8-tetrakis-[trifluormethyl]- E16a, 566 (Azin-1,2-Cycloalkyl.)... 

The reaction of alkenes with acetyl hypofluorite436-439 or with fluorine,451-473-474 2,3,4,5,6-pcntachloro-l-fluoropyridinium trifluoromelhanesulfonate ((V-FPCPy-OTf),441-711 cesium fluoroxysulfate,435 (V-fluorobis(triflyl)amine432 or l-(chloromethyl)-4-fluoro-l,4-diaza-bicyclo[2.2.2]octane tetrafluoroborate431 in acetic acid leads to the simultaneous addition of fluorine and the acetoxy group across the double bond. Examples of these additions are summarized in Table 34. Further examples are the formation of l439 and 2 439... 

While most tertiary amine catalysts are effective approximately in proportion to their base strength, an exception is triethylene diamine, 4-diaza[2.2.2]bicyclo-octane). As shown by Farkas et al. [142,143] this catalyst is much more powerful than would be predicted from its base strength, being five times stronger as a catalyst than iV,JV -dimethyl-piperazine, which has slightly greater basicity. It was first suggested that the explanation may be the complete lack of steric hindrance in the structure. 

Fluorescence of tertiary amines has been observed by Phillips and co-workers (220), Tsumbomura and co-workers (112), and Halpern and co-workers (221-223,294). Fluorescence is reported from tertiary, but not secondary or primary, amines (220), presumably because of the ease with which the amino group can lose an H atom in these compounds (220). Fluorescence has been observed in hydrocarbon solution (112) as well as the vapor phase, with comparable quantum yields (222). For 1,4-diaza-bicyclo-[2,2,2]octane Che fluorescence quantum yields are 0.9 (vapor) and... 

Tertiary a-halo ketimines 3 reacted with alcohols in the presence of nitrogen bases, e.g. triethylamine, 1,4-diazabicyclo[2.2.2]octane, l,5-diazabicyclo[4.3.0]non-5-ene or 1,8-diaza-bicyclo[5.4.0]undec-7-ene, to afford mainly l-alkoxy-2,2-dialkylcyclopropylamines 4, together with variable amounts of a-alkoxy ketimines 5 and rearranged a-amino acetals 6. The geminal functionalized cyclopropanes 4, obtained in up to 80% yield, and the a-alkoxy ketimines 5, were formed via intermediate 2-(alkylamino)allylcarbenium ions 7. 

A novel titanium containing zeolite mordenite has been synthesized hydrothermally using 1,4 diaza bicyclo 2,2,2 octane (DABCO) as a templating agent for the first time. Physicochemical characterization of the sample showed that Ti atoms are part of the framework, probably in tetrahedral co-ordination. These zeolites have been found to be active catalysts in phenol hydroxylation with hydrogen peroxide as an oxidant. 

Die Hydrogenolyse von 4-Oxo-2,7-dimethyl-l,5-diaza-bicyclo[3.3.0]octan fiihrt unter Spaltung der Ringbriicke zu 4-Oxo-2,7-dimethyl-l,5-diazocan (64% d.Th.) ... 

Chlor-propyl)-2,4-dioxo-5-methyl-imidazolidin bildet durch intramolekulare N-Al-kylierung (vgl. S. 521) 2,4-Dioxo-5-methyl-l,3-diaza-bicyclo[3.3.0]octan, das sich zu 2-Methyl-DL-prolin hydrolysieren laBt. Die benotigte Vorstufe erhalt man durch Bucherer-Reaktion (s.S. 538) mit l-Hydroxy-4-oxo-pentan5 ... 

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