Cyclopropanimine, V. Ringsubstituierte Cyclopropanimine aus α‐Bromketiminen

Quast, Helmut; Frank, Rolf; Heublein, Alfred; Schmitt, Edeltraud

doi:10.1002/jlac.198019801120

Cited by 26 publications

(11 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After stirring for 15 min a solution of rac-2,3,3-trimethylbutanol [18] (0.58 g, 5.0 mmol) in dichloromethane (10 mL) was added dropwise. Stirring was continued for 15 min at À 50 8C.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

On the Constitutional Stability ofη1-Allylmetal Compounds

Hoffmann

Polachowski

1998

Chem. Eur. J.

View full text Add to dashboard Cite

Many h 1 -allymetal species undergo a rapid haptotropic rearrangement. The stereochemical outcome of reactions of these allylmetal species with aldehydes depends on whether the haptotropic rearrangement is faster or slower than the reaction with the aldehyde. We present here a test system based on kinetic resolution, by which just this information becomes available. Thus, haptotropic rearrangement of cyclohexenyllithium, -magnesium chloride, -titanium triisopropoxide, and -titanium tetraisopropoxide, was found to be faster than addition to the aldehyde 9. Borotropic rearrangement in cyclohexenyldiethylborane was found to be slower than the addition to the aldehyde 9.

show abstract

“…After stirring for 15 min a solution of rac-2,3,3-trimethylbutanol [18] (0.58 g, 5.0 mmol) in dichloromethane (10 mL) was added dropwise. Stirring was continued for 15 min at À 50 8C.…”

Section: Methodsmentioning

confidence: 99%

“…The racemic aldehyde 9 was prepared by oxidation of 2,3,3-trimethylbutanol. [18] The synthesis of the enantiomerically pure aldehyde 9 started with the alkylation of the Evans [19] Scheme 3. Synthesis of 9 starting from acyloxazolidinone 14.…”

Section: Development Of the Test Reactionmentioning

confidence: 99%

On the Constitutional Stability ofη1-Allylmetal Compounds

Hoffmann

Polachowski

1998

Chem. Eur. J.

View full text Add to dashboard Cite

show abstract

“…[13] Although cyclopropenone 1 ['I has been known for several decades, and the first synthesis of the methylenecyclopropene 2['] was reported a few years ago, only plausible indications but no unequivocal proof could be found for derivatives of the aza compounds 3i31 and 4a.i4. We report here on the first trapping reactions which confirm the existence of 2-methylene-2H-azirine 4 a as well as on the methyleneazirine derivatives 4 b-d and their spectroscopic data.…”

mentioning

confidence: 99%

2‐Methylene‐2H‐azirines by Photolysis of 1‐Azidoallenes

Banert

Hagedorn

1990

Angew. Chem. Int. Ed. Engl.

View full text Add to dashboard Cite

“…Clearly, the direction of cyclisation of the aziridine rings reflects the relative stabilities of the corresponding carbocyclic systems. [21] [27] We note in passing, that some other heteroanalogues of 6-methylenebicyclo[3.1.0]hexane [28] and 7-methylenebicyclo[4.1.0]heptane [29] are already known. An interpretation of the (E/Z) diastereoselectivity in the formation of the exocyclic imines 14, 16, and 18 is less straightforward.…”

Section: Discussionmentioning

confidence: 99%

“…sult from the photoextrusion of molecular nitrogen. Ir-and, so far, only nitrogen analogues of trimethylenemethane (28).…”

mentioning

confidence: 99%

Photoextrusion of Molecular Nitrogen from Annulated 5-Alkylidene-4,5-dihydro-1H-tetrazoles: Annulated Iminoaziridines and the First Triplet Diazatrimethylenemethane

Quast¹,

Fuss

Nüdling

1998

Eur. J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

Deprotonation of the annulated tetrazolium salts 4, 6, 8, 10, and 12 with sodium or potassium hydride yields the alkylidenedihydrotetrazoles 5, 7, 9, 11, and 13, respectively. While 5a and b are unstable, even in solution at low temperatures, 7, 9, 11, and 13 form yellow oils that are distilled under high vacuum. − Irradiation of solutions of 7, 9, and 11 in [D8]toluene at −60°C yields, besides molecular nitrogen, annulated iminoaziridines that have an exocyclic CN double bond, i.e. 14, 16, and 18, respectively. In addition, an equal amount of the isomer 19 with the endocyclic CN double bond is formed from 11. On thermolysis, 14, 16, and 18 undergo [2 + 1] cycloreversion into methyl isocyanide and the cyclic imines 15, 17, and 20, respectively. By contrast, 19 rearranges thermally to yield 18. While the doubly bridged alkylidenedihydrotetrazole 13a affords only unidentified decomposition products on photolysis, its methyl homologue 13b is converted into the hexahydronaphthyridine 22 which is also formed on thermolysis. − Irradiation of 13b in a 2‐methyltetrahydrofuran or butyronitrile matrix at 77 K yields a triplet diradical showing a four‐line EPR spectrum centred at 3362 G and a half‐field transition (at 1669 G) with a hyperfine structure. The zero‐field splitting parameters |D‐hc| = 0.031 cm−1 and |E‐hc| = 0.0014 cm−1 are obtained by simulation of the EPR spectrum. The signal‐carrier is assigned the diazatrimethylenemethane structure 23 on the basis of the close similarity between its EPR spectrum and those of trimethylenemethane (28) and tris(N‐methylimino)methane (29). − Structural features are discussed that are responsible for the observed differences between the photochemical pathways.

show abstract

Cyclopropanimine, V. Ringsubstituierte Cyclopropanimine aus α‐Bromketiminen

Abstract: N-Alkyl-und N-Arylcyclopropanimine 9 erha'lt man in guter Ausbeute aus den a-Bromketiminen 8 durch 1,3-EIiminierung von Bromwasserstoff mit iiberschiissigem Kalium-terf-butylat in Tetrahydrofuran. Aus dem a-Bromcyclohexanimin 14 entsteht das vom Bicyclo(3.

Cited by 26 publications

References 87 publications

On the Constitutional Stability ofη1-Allylmetal Compounds

On the Constitutional Stability ofη1-Allylmetal Compounds

2‐Methylene‐2H‐azirines by Photolysis of 1‐Azidoallenes

Photoextrusion of Molecular Nitrogen from Annulated 5-Alkylidene-4,5-dihydro-1H-tetrazoles: Annulated Iminoaziridines and the First Triplet Diazatrimethylenemethane

Contact Info

Product

Resources

About