Trans-2-phenyl-3- aziridine

Dihydrooxazoles are quite rare they are produced by the thermal rearrangement of C-acylaziridines (equation 161). Both cis- and trans-2-benzoyl-l-cyclohexyl-3-phenyl-aziridine react with diphenylcyclopropenone to yield compound (302 equation 162). ITie... 

Important synthetic paths to azirines and aziridines involve bond reorganization, or internal addition, of vinylnitrenes. Indeed, the vinylnitrene-azirine equilibrium has been demonstrated in the case of trans-2-methyl-3-phenyl-l-azirine, which at 110 °C racemizes 2000 times faster than it rearranges to 2-methylindole (80CC1252). Created in the Neber rearrangement or by decomposition of vinyl azides, the nitrene can cyclize to the p -carbon to give azirines (Scheme 4 Section 5.04.4.1). 

Aziridine, 3-benzoyl-trans-A/-benzyl-2-phenyl-irradiation, 7, 62... 

AZIRIDINE, trans-l-ammo-2,3-diphenyl-[1-Azindinamme, trans-(i)-2,3-di-phenyl-], 55,53, 114 AZIRIDINE, frans-2,3-diphenyl-l-phthal-linido- [ l//-Isoindole-l,3(2//)-dione, trans-( )-2-(2,3-diphenyl-1 -azindin-yl) 1,55, 115... 

Internal phenyl-substituted alkenes present significant problems for this catalyst system. Although enantioselectivities with both trans (70% ee, Eq. 56) and cis (60% ee, Eq. 58) P-methylstyrene are moderate, cis alkene provides the trans aziridine as the major product. Furthermore, 15% of the recovered alkene is isomer-ized (77). Internal dialkyl alkenes are not prone to this isomerization. 

Highly substituted chalcones and one equivalent of NH2OH afforded substituted trans-2-benzoyl-3-phenyl-1H-aziridines . ... 

Scheiner has shown that triazolines undergo both direct and sensitized photoelimination of molecular nitrogen to yield aziridines.463 With the triazolines prepared from phenyl azide and cis- or trans-fi-methylstyrene, direct photolysis produces a mixture of aziridines in which the starting geometry has been largely retained. Sensitized photolysis, however, is totally nonstereospecific. 

The photoreaction characteristic of epoxyketones is not observed in the corresponding aziridine or thiirane derivatives. In the compounds so far examined, the result of photolysis is usually photo-extrusion of the heteroatom. In this way, trans-1 -cyclohexyl-2-phenyl-3-benzoylaziridine is converted in aqueous ethanol into a... 

Aziridine, tran.s-2-benzoyl-1 -cyclohexyl-3-phenyl-UV, 7, 50 (66JOC1244, 75JA2822)... 

In another study, the reaction of trimethylsilyl azide, chloride, or iodide with /V-iosylaziridines in DMF opened the aziridine ring by attack at the least substituted carbon giving the trans product in high yield.47 However, when a phenyl group was on the aziridine ring, both possible products were obtained and attack at the benzyl carbon predominated. 

From the ratios of cis- and trans-N-carbethoxy-2-methyl-3-isopropylaziri-dines (38) and (39) it was concluded that 30% of the photochemically generated nitrene was formed in the triplet state 86>. With a-methylstyrene (40), which was used as triplet trap, carbethoxynitrene does not lead to aziridines. As 1 1 adduct 3-carbethoxyamino-2-phenyl-propene-l (42) was isolated 83>, which was pre-... 

Lithio-fluoro (or -chloro) methyl phenyl sulfoxide reacts with iV-(benzylidene)aniline derivatives (105) to afford the corresponding aziridines (106) in good yields. Two diastereomeric isomers are produced, but the trans isomer is the major product except in the case of iV-benzylidene-p-nitroaniline (Scheme 30). ... 

Interestingly, both cis and trans aziridine isomers gave the same azirine ester 68, surprising as the C2 proton is more acidic than the C3 proton and would also result in conjugation with the ester functionality. The intermediate 69 is shown for the cis aziridine. R groups included alkyl chains and phenyl substituents and yields varied from 54% to 86% with higher yields obtained via the trans aziridines. 

Isocyanide, benzyl-, 55, 98 Isocyanide, butyl-, 55, 98 Isocyanide, cyclohexyl-, 55,98 ISOCYANIDE, 1,1-dimethylethyl- [Isocyanide, ferr-butyl-], 55,96 Isocyanide, dodecanyl-, 55,98 Isocyanide, ethyl-, 55,98 Isocyanide, methyl-, 55, 98 Isocyanide, phenyl-, 55, 98 1/f-Isoindole-l, 3(2/I)-dione, 2-amino-[Phthalimidc, N-amino-j, 55, 115 l/y-ISOINDOLE-l,3(2//)-DIONE, trans- ( )-2-(2,3-diphenyl-l-aziridinyl)-[Aziridine, frans-2,3-diphenyl-l-phthalimido-], 55, 115 ISOXAZOLE, 3-(4-chlorophenyl)-5-(4-methoxyphenyl)-, 55, 39 Isoxazole, 5-C4-chlorophenyl)-3-(4-meth-oxyphenyl)-, 55, 42... 

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