Synthese und Struktur eines Spiro[adamantan‐aziridin]imins

Abstract

Spiro[adamantan-aziridinlimin 3 entsteht regioselektiv und in hoher Ausbeute, wenn das aBromimidoylchlorid 1 in einer Eintopfreaktion nacheinander rnit terl-Butylamin und Kaliumtert-butylat umgesetzt wird. 3 kristallisiert orthorhombisch in der Raumgruppe P212121 mit 8 Molekulen pro Elementarzelle. Die asymmetrische Einheit enthalt zwei unabhangige Molekiile, die Enantiomere sind. Die Molekule besitzen die auch in Losung uberwiegende Q-Konfiguration. Die Bindung zum Substituenten am Aziridinstickstoff ist nur urn 40" aus der Dreiringebene ausgelenkt. Bindungslangen und -winkel sowie IR-Frequenzen werden im Zusammenhang diskutiert. Synthesis and Structure of a SpiroIadamantane-aziridinelimine')In a single pot reaction by means of tert-butylamine followed by potassium tert-butoxide the abromoimidoyl chloride 1 is converted into the crystalline spiro[adamantane-aziridinelimine 3 regioselectively in high yield. 3 crystallizes orthorhombically in the space group P2,2,2, with 8 molecules per cell. Two independent enantiomorphic molecules build the asymmetric unit. In the solid state, the molecules have the (@-configuration which also predominates in solution. The angle between the three-membered ring-plane and the direction of the tert-butyl nitrogen bond is only 40 ". The relationships of bond lengths and angles with IR frequencies are dicussed.Strukturparameter gespannter Molekule2) sind besonders interessant, da der energetische Begriff Spannung geometrische Aquivalente bei Bindungsabstanden und -winkeln besitzt. Deren Kenntnis ist fur die Interpretation der chemischen und spektroskopischen Eigenschaften dieser Verbindungen sowie zum Vergleich rnit theoretischen Berechnungen von Bedeutung. Zu den sehr energiereichen kleineren Molekiilen zahlen die Methylencyclopropane rnit einer Spannung von ca. 40 kcal/mo13). In der gleichen GroRenordnung durfte die Spannung ihrer Heteroanalogen liegen. Wir berichten hier uber die Synthese und Rontgenstrukturbestimmung eines heteroanalogen Methylencyclopropans, des Aziridinimins 3.Aziridinimine (Aziridinylidenamine) entstehen glatt aus N,N'-disubstituierten aBromamidinen durch 1,3-Eliminierung von Bromwasserstoff rnit Hilfe einer starken Base4). GroRe Substituenten erleichtern die Isolierung und Handhabung durch Verminderung der Reaktivitat. Besitzt das a-Bromamidin verschiedene N-Substituenten, mul3 rnit der Bildung von Gemischen zweier Strukturisomerer gerechnet werden4).

exo/endoPreferences of Double Bonds in Three-Membered Ring Compounds − The Bias Toward Endocyclic Unsaturation in 3-Alkyl- and 3-Amino-2H-azirines: A Theoretical and Experimental Study

“…[14] An X-ray diffraction analysis of a substituted iminoaziridine [40] and the computed geometries for (E)-and (Z)-4 [16] agree that the ring nitrogen atom adopts a pyramidal conformation. While all three tautomers 3a and (E)/ (Z)-4 possess amidine moieties, the planar amino group of 3a is a much better donor than the pyramidal ring nitrogen atom of (E)-and (Z)-4.…”

Synthesis, Configuration, and15N NMR Spectra of Iminoaziridines. Synthons Equivalent to Three Components of the Ugi Reaction

“…So far, the configuration of only a single iminoaziridine was established unequivocally, viz., that of ( E )- 5 in the solid state by X-ray crystallography . The assignment of E - and Z -configurations to the major and minor diastereomers of 1a , 1g , and 16 8b was based on the relative size of the homoallylic 1 H− 1 H coupling between the ring proton and the imino methyl group, i.e., 5 J trans > 5 J cis , and relative asymmetric solvent- induced shifts (ASISs): 33 asymmetric solvation of the imine moiety by benzene shifts resonances of protons that reside at the side of the imino alkyl group stronger to high field than protons at the side of the lone pair.…”

“…However, dehydrobromination of N -ethoxycarbonyl-, N -phosphoryl-, and N -sulfonyl-substituted α-bromoamidines did not yield iminoaziridines rather than five-membered heterocycles . For physical organic chemistry studies, a few examples of types 1 3,4 and 4 ,,, and the spirocyclic iminoaziridine 5 have been prepared in this way. To foster synthetic applications, we detail here the synthesis of 1 and 4 with various N -substituents and of diastereomeric iminoaziridines exo - and endo - 6 .…”

4,8,9,10-Tetraphenyl-1,3-diazaadamantan-6-one acetone hemisolvate

“…The benzene layer was separated, washed thoroughly with water, and evaporated to yield the crude adamantanone. This was recrystallized from a 2:2:1 mixture of benzene, chloroform and acetone and the melting points were noted (Quast & Mu È ller, 1980;Jackman et al, 1982;Quast et al, 1982;Sivasubramanian et al, 1990;Jeyaraman et al, 1992). Colourless single crystals were obtained as transparent needles from a saturated solution of the title compound in chloroform, benzene and acetone, by slow evaporation at room temperature.…”