Reactivity of Tri‐tert‐butylazete

Abstract

The first kinetically stabilized azete, the title compound 1, is sensitive toward oxidation (→ formation of the dioxetane 2) and undergoes hydrolysis to the β‐imino ketone 3. Sterically nondemanding cycloaddition partners such as cyclopentadiene or diazomethane (CH2N2) (→ formation of the adduct 4) attack at C‐2/C‐3, whereas those with bulky groups such as acetylenedicarboxylate esters or tert‐butylphosphaacetylene (PCtBu) (→ formation of the bicyclic compound 5) react at N‐1/C‐4.

Reactions of quadricyclane with fluorinated nitrogen-containing compounds. Synthesis of 3-aza-4-perfluoroalkyl-tricyclo[4.2.1.02,5]non-3,7-dienes

“…IR spectra of 11-13 exhibit weak absorption $1600-1615 cm À1 assigned to C=N (cf. 1590 cm À1 for endo-3-aza-2,4,5-tris(tertbutyl)tricyclo[4.2.1.0 2,5 ]non-3,7-diene [18]). Each 1 H spectrum of compounds 11-13 containing eight well-separated signals of equal intensity, exhibits resonance of vinyl protons at 6.2-6.3 ppm (H-7, H-8, see Eq.…”

“…Despite the fact that cycloadducts of 1 with both acetylenes [1][2][3] and azocompounds [5,6] are known for over 30 years, the only reported representative of 3-azatricyclo[4.2.1.0 2,5 ]non-3,7-dienes is endo-3-aza-2,4,5-tris (tert-butyl)tricyclo[4.2.1.0 2,5 ]non-3,7-diene, prepared by reaction of tri-tert-butylazete and cyclopentadiene [18].…”

Organophosphorus Compounds; 129. Mesitylphosphaacetylene: Synthesis and Reactivity Studies of a New Phosphaalkyne

“…As is the case of the Dewar-2-phosphabenzene 20, the 31 P NMR signal of the 1-aza derivative 22 at δ = 230.4 shows a dramatic low field shift (∆δ = +28.2 compared to tert-butyl substitution). 28 The 13 C NMR resonances and J(C,P) coupling values of the skeletal carbon atoms are in good accord with those of the tert-butyl derivative, with the exception of C2: the phosphaalkene carbon atom is found at δ = 225.9, i.e., a remarkable upfield resonance shift (∆δ = -16.9) (Table).…”

“…Just as the reactant pair "cyclobutadiene/acetylene" opened an access to the chemistry of the valence isomers of benzene, 26 valence isomers of (hetero)phosphabenzenes are obtained by using alkyl-substituted phosphaalkynes and cyclic 1,3-dienes such as 19 27 and 21. 28 Mesitylphosphaacetylene (1b) undergoes an analogous reaction with the kinetically stabilized cyclobutadiene-carboxylate 19 to give the 2-Dewar-phosphinine 20 regioselectively and in quantitative yield. However, purification of the bicyclic compound 20 by bulb-to-bulb distillation is not possible due to thermal decomposition at the required high temperatures.…”

2H-Azirines as Synthetic Tools in Organic Chemistry

“…2 H ‐Azirines can also be obtained from azete derivatives. These heterocycles are oxidized by dimethyl sulfoxide to give the 2 H ‐azirine directly or, alternatively, they can be treated with 1‐diazo‐1‐phenylethane to form the intermediate bicyclic adduct which then rearranges on thermal or photochemical treatment to generate hydrazono‐2 H ‐azirines 41…”