Diaza octane

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. 

The Postnitrated Polyurethane Polymer of 3,6-Dinitro-3,6-Diaza-1,8-Octane Diisocyanate and... 

Scheme 54 Synthesis of (2/t,55)-l,3-diaza-2-chloro-3-phenyl-2-phosphabicyclo[3.3.0]octane 198...

Almost diastereomerically pure (2i ,55)-l,3-diaza-2-methoxy-3-alkyl-2-phosphabicyclo[3.3.0]octanes (201a-d) were formed in the reaction of (S)-2-anilinomethyl)-pyrrolidines (197b-e) with methyl dichlorophosphite in the presence of NEt3 (Scheme 55) [86], With these ligands, high stereoselectivity (ee s up to 91%) was observed in the Pd catalyzed ally lie animation reaction [86],... 

Diastereomerically pure (2W,5.V)-l,3-diaza-2-(2-methylphenyl)-3-phenyl-2-phosphabicyclo[3.3.0]octane (.S )-202] was formed in the thermal reaction of (S)-2-(anilinomethyl)pyrrolidines (197a) with o-TolP(NMe2)2 and isolated in 27% yield after recrystallization (Scheme 56) [87], Its cyclopalladation with palladium diacetate followed by anion metathesis gave dimer (5,5)-203 (Scheme 56) [87],... 

A useful method for large-scale synthesis of diastereomerically pure (2R,5S)-3 -phenyl-2-(8-quinolinoxy)-1,3-diaza-2-phosphabicyclo[3.3.0]octane (205) was based on a similar reaction of tris(dimethylamino)phosphine with (5)-197a generating the intermediate 204 which, by addition of 8-hydoxyquinoline followed by additional refluxing gave the final product. Recrystallization of the crude reaction mixture afforded diastereomerically pure 205 as a solid, stable to air and moisture in 98% yield (Scheme 57) [88], It was converted to complex 206 by mixing with... 

A number of 1,3,2-diazaphospholidinc derivatives 264-265 having (5S)-1,3-diaza-2-phospha-2-oxo-3-phenylbicyclo[3.3.0]octene moiety (labeled as P) were prepared using diastereomerically pure (5.S)-1,3-dia/a-2-chloro-2-phospha-2-oxo-3-phenylbicyclo[3.3.0]octane (263) as a key substrate. Its preparation was in turn based on the reaction of phosphoryl chloride with (-)-197 (Scheme 63) [96-100]. 

Synthesis of 2,2,4,4-Tetra-ferf-butyl-1,3-diaza-2,4-disilabicyclo[3.3.0]octane 318... 

Under drastic thermal conditions, the iminosilane-LiF adduct 82 eliminates LiF and the iminosilane intermediate 83 rearranges intramolecularly by C-H bond insertion affording 2,2,4,4-tetra-/i /Z-butyl-l,3-diaza-2,4-disilabicy-clo[3.3.0]octane 84 in 87% yield (Equation 6) <1996JOM203>. 

A combination of the alkyne cyclotrimerization catalyzed by RhCl(PPh3)3 with a 1,3-dipolar cycloaddition provides rapid access to 3-dihydroindenylmethyl-3,7-diaza[3.3.0]-octane 61 in excellent yield thus five new bonds, four stereocenters, and three rings are created in a one-pot operation (Scheme 7.18) [41]. 

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 ... 

According to Wright et al. [44] DPT can also yield 3,7-dinitro-3,7-diaza-l, 5-dioxacyclo-octane (m.p. 263-264°C) under action of nitric acid (99%) and ammonium nitrate ... 

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