3-phenyl-2H-azirine

PHENYL-2H-AZIRINE-2-CARB0XALDEHTDE [2ff-Azirine-2-cu boxaldeh7de, 3-phenyl-]... 

C. 2-(Dimethoxymethyl)-3-phenyl-2H-azirine. The crude product (71-75 g., 0.32-0.34 mole) obtained from Part B is heated at reflux in 11. of chloroform in a 2-1., round-bottomed flask for 12 hours (Note 9). The solvent is removed with a rotary evaporator and the crude residue... 

The aldehyde functionality present in 3-phenyl-2H-azirine-2-carbox-aldehyde reacts selectively with amines and with Qrignard and Wittig reagents to give a variety of substituted azirines. These azirines have been used, in turn, to prepare a wide assortment of heterocyclic rings such as oxazoles, imidazoles, pyrazoles, pyrroles, and benzazepins. ... 

The formation of pyrazoles from reactions of suitably substituted 2-arylazirines and molybdenum hexacarbonyl has been discussed earlier in this section (see Schemes 89, 90)47 an analogous procedure depicting the transformation of 2-formyl-3-phenyl-2H-azirine into 3-phenylisoxazole is illustrated in Scheme 109.47... 

Wird die Ringerweiterung statt mit Bortrifluorid mit Meerwein-Reagens durchgefuhrt, so erhalt man mit Benzonitril aus 2-Methyl-3-phenyl-2H-azirin hauptsachlich l-Ethyl-2,5-diphe-nyl-4-methyl-imidazol und aus 3-Methyl-2-phenyl-2H-azirin 1-Ethyl-2,4-diphenyl-5-methyl-imidazol44°. 

Die Ringoffnung von Azirinen mit Fluorwasserstoff/ Pyridin verlauft je nach Substitution und Bedingungen unterschiedlich2,5> 6 unter Bildung von Pyrazinen, a-Fluor-ketonen und/oder 2,2-Difluor-alkylaminen. So erhalt man z.B. aus 2-Methyl-3-phenyl-2H-azirin 2-Amino-1,1-difluor-l-phenyl-propan als Hauptprodukt5. 

Irradiation of 3-phenyl-2H-azirines (2) with triphenylvinylphosphonium bromide (3) in acetonitrile forms 2H-indoles (4) (equation 3)29. The probable mechanism of formation of 4 leads, via benzonitrile ylide and 1,3-dipolar cycloaddition, to the C C double bond of the vinylphosphonium bromide via the assumed intermediate (5). 

Triphenylvinylphosphonium salts are usually used as dipolarophiles against azides and diazoalkanes30. 2,3-Diphenyl-2//-azirine and 1-azido-l-phenylpropene as precursors of 2-methyl-3-phenyl-2H-azirine produce, after irradiation, 2,5-diphenylpyrrole and 2-methyl-5-phenylpyrrole, respectively29. 

A practical resolution of 3-phenyl-2H-azirine-2-methanol 15 at a very low temperature (-40 °C) was reported by Sakai et al64 to enhance the enantioselectivity in immobilized lipase-catalyzed resolution of 15 using vinyl butanoate as acyl donor in ether as organic solvent. The method was found to be effective in enhancing the enantioselectivity E and affords the primary alcohol (S)-15 with 99% ee and the ester (A)-16 with 91% ee. 

The only example of the ring system of Type I was prepared by Woemer et al. when 3-phenyl-2H-azirine (1) was treated with diphenylketene-/ -tolyli-mine (2) in benzene at 65 °C for 65 h besides benzophenone, a 1 1 isomeric mixture of the azirino[ 1,2-c]quinazoline 3 and the 1,3-benzodiazepine 4 was formed. During heating in trichlorobenzene under a nitrogen atmosphere. 

Sakai,T. Kawabata, I. Kishimoto,T. Ema,T. Utaka, M., Enhancement of the Enantioselectivity in Lipase-Catalyzed Kinetic Resolution of 3-Phenyl-2H-azirine-2-methanol by Lowering the Temperature to —40 °C. J. Org. Chem. 1997, 62,4906. 

Orton, E., Collins, S. T., Pimentel, G. C., Molecular Structure of the Nitrile Ylide Derived from 3 Phenyl 2H azirine in a Nitrogen Matrix, J. Phys. Chem. 1986, 90, 6139 6143. 

Similarly, benzonitrile ylide (38) was obtained by photolysis of 3-phenyl-2H-azirine at 8K and characterized by its IR spectrum (vmax 1930 cm-1) (Eq. 12).49... 

The first known heterocyclic analog of bicyclobutane, 3-phenyl-1-azabicyclo-fl.l.OJbutane (8), has been obtained in 60% yield by the reaction of 3-phenyl-2H-azirine (7) with dimethylsulfonium methylide in dry THF at — 10°.1M The reaction of... 

Irradiation of 4,4-dimethyl-2-phenyl-2-thiazolin-5-thione (136) in the presence of 2,2-dimethyl-3-phenyl-2H-azirine yields a mixture of 3 (1 s 1) adducts (137-139). Formation of (137) and (139) can be explained in terms of a 1,3-dipolar cycloaddition of PhC=N-C(CH3)2 to the C=S of (136), while 038) arises from photolysis of (136). Irradiation of the azirine and CS2 gives a mixture of (2s 1) adducts for one of which the structure has... 

When a solution of 3-phenyl-2H-azirine in excess methyl acrylate or acrylonitrile is photolyzed, 2-phenyl-4-substituted-l-pyrroline is obtained (Scheme 5.35). 

As unusual aspect of the intramolecular photocyclization of 2-allyl-substituted 2/f-azirines was uncovered during a study of the photochemistry of -2-(2-butenyl)-2-methyl-3-phenyl-2H-azirine (185). Irradiation of 185 in cyclohexane gave rise to one major product (>95%) which was identified as nrfo-3,6-dimethyl-l-phenyl-2-azabicyclo[3.1.0]hex-2-ene (186). The formation... 

The parent compound 2H-azirine is thermally unstable and has to be stored at very low temperatures. Substituted 2H-azirines are more stable. They are liquids or low melting solids. Their basicity is substantially lower than that of comparable ahphatic compounds. For instance, 2-methyl-3-phenyl-2H-azirine is not soluble in hydrochloric acid. 

Attempts to prepare 3-phenyl-2H-azirine-2-methanol trifluoroacetate (28) by treating hydroxymethyl derivative 29 with TFAA and triethylamine produced 1 -phenyl-2-(trifluoroacetylamino)prop-2-en-1 -one (30,30 %) and 2-trifluoromethyl-4-trifluoroacetoxymethyl-5-phenyloxazole (31, 60 %) [28],... 

Azabicyclo[1.1.0]butanes. 3-Phenyl-2H-azirine added dropwise with stirring at -10° under N, during 25 min, to a soln. of dimethylsulfonium methylid prepared according to E. J. Corey and M. Chaykovsky, Am. Soc. 87, 1353 (1965)... 

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