Synthesis and cycloaddition reactions of 2-(2-thienyl)aziridines

Lown, J. William; Matsumoto, Kouzou

doi:10.1139/v70-370

Cited by 26 publications

(6 citation statements)

References 16 publications

(19 reference statements)

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“…spectrum of the acid 10 in carbon tetrachloride at different concentrations showed no evidence of intra-molecular hydrogen bonding such as might have been expected had the reverse mode of addition been adopted (6). The conclusions reached above with respect to the orientation of the addition of methyl propiolate in 6 are in agreement with studies of the addition of olefinic dipolarophiles to 2-(2'-thieny1)aziridines in which bulky addends were found to adopt positions remote from the 3-aroyl group which presumably exerts greater steric hindrance than does the 2-(2'-thienyl) group in this type of addition (1).…”

Section: (A) Acetylenic Dipolarophilessupporting

confidence: 82%

“…We have recently described the preparation of the hitherto unknown 2-(2'-thieny1)aziridines (1) and have shown that, despite the lower resonance energy of the thiophene ring (20 kcal mole-' (2)) compared with benzene, 2-(2'-thieny1)-3-aroylaziridines undergo thermal cleavage of the 2-3 bond of the aziridine ring to azomethine u ylides at moderate temperatures. The transient dipoles could be trapped with olefinic dipolarophiles affording 2-(2'-thieny1)pyrrolidines.…”

mentioning

confidence: 99%

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1,3-Dipolar cycloaddition reactions of 2-(2′-thienyl)aziridines

Lown¹,

Matsumoto²

1970

Can. J. Chem.

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The 1,3-dipolar cycloaddition of 2-(2'-thieny1)aziridines to a series of acetylenic and heterornultiple dipolarophiles leading to a series of new linked heterocycles is described. The versatility of these reactions suggests a general synthetic route to linked heterocycles.Canadian Journal of Chemistry, 48, 3399 (1970) We have recently described the preparation of the hitherto unknown 2-(2'-thieny1)aziridines (1) and have shown that, despite the lower resonance energy of the thiophene ring (20 kcal mole-' (2)) compared with benzene, 2-(2'-thieny1)-3-aroylaziridines undergo thermal cleavage of the 2-3 bond of the aziridine ring to azomethine u ylides at moderate temperatures. The transient dipoles could be trapped with olefinic dipolarophiles affording 2-(2'-thieny1)pyrrolidines.We report the examination of 1,3-dipolar cycloadditions of 2-(2'-thieny1)aziridines to acetylenic and heteromultiple bonds as a first approach to a general synthesis of linked heterocycles. (a) Acetylenic DipolarophilesBoth cis-and trans-3-benzoyl-l-cyclohexyl-2-(2'-thieny1)aziridine (1) reacted with dimethyl ~6~1 1 3 yl-3-deutero-2-(2'-thieny1)aziridine (91 % deuterium incorporation) gave 5 in which both branches of the 12 Hz AB quartet due to the methine protons were diminished to an equal extent (20 %). This discounts the trans-3-pyrroline structure 4 for the compound (which is in any case unlikely in view of the magnitude of the methine coupling) which would be expected to show one branch of the AB quartet diminished I C6Hll

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Section: (A) Acetylenic Dipolarophilessupporting

confidence: 82%

mentioning

confidence: 99%

1,3-Dipolar cycloaddition reactions of 2-(2′-thienyl)aziridines

Lown¹,

Matsumoto²

1970

Can. J. Chem.

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“…Arnold and Karnischky have recently shown that the carbonyl ylide derived from the thermal cleavage of 5-oxabicyclo [2,1,0]-pentane forms a mixture of exo and endo adducts with maleonitrile (27). The endo preference for 1 is in agreement with the results obtained with the indanoaziridine 6 (32,38) and removes the apparent discrepancy between the hitherto observed orientation of additions to 1 and 6.…”

Section: Discussismsupporting

confidence: 71%

Reactions of Carbonyl Ylides

Lown¹,

Matsumoto²

1971

Can. J. Chem.

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2,3-Diphenylindenone oxide 1 undergoes thermal 1,3-dipolar cycloadditions via a carbonyl ylide with symmetrical olefinic dipolarophiles to give (i) with cis addends mixtures of endo and exo adducts in which endo adducts generally predominate in agreement with results obtained with l-cyclohexyl-6-(cyclohexylimino)-la-phenylindano[l,2-b]aziridine and (ii) with trans addends adducts in which the 2-exo-3-endo product predominates. The pyrilium oxide 4is efficiently trapped with benzyne. 1,3-Diphenylisobenzofuran reacts with cis-addends to give endo-exo mixtures in which the endo adducts generally predominate. 2-Acetyl-5,5-pentamethylene-2-phenyl-A3-l,3,4-oxadiazoline undergoes regiospecific cycloaddition via a carbonyl ylide with unsymmetrical olefinic dipolarophiles in accordance with substituent electronic effects, and with 1,4-naphthoquinone a previously postulated type of intermediate adduct is isolated. L'oxyde de diphenylindenone-2,3 1 peut reagir pour donner des cycloadditions dipolaires-1,3 thermiques, par l'intermediaire d'une ylure de carbonyle possedant des dipolarophiles olefiniques symetriques. On obtient ainsi (i) avec des melanges endo et exo des produits cis, des produits d'addition oh la forme endo predomine habituellement, en accord avec les resultats obtenus avec le cyclohexyl-1 (cyclohexylimino)-6 phenylindano-la aziridine[l,2-b] et (ii) avec les produits trans, des produits d'addition oh la forme exo-2-endo-3 predomine. L'oxyde de pyrilium 4 peut &tre recueilli efficacement dans le benzene. Le diphCnylisobenzofuranne reagit avec les produits cis pour donner des melanges endo-exo, oil les produits d'addition endo prkdominent generalement. Le 2-acetyl-5,5 pentamethylene-2 phenyl-A3-1,3,4-oxadiazoline peut reagir pour donner des cycloadditions rtgiospecifiques, via une ylure de carbonylepossedant des dipolarophiles olefiniques non-symetriques, selon les effets dlectroniques du substituant; avec la naphthoquinone-1,4, on isole un produit d'addition intermediaire postule precedemment.

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“…Compound (I) was prepared from ethyl (2E)-3-(2-chloro-6,7dimethylquinolin-3-yl)acrylate in two steps according to a literature method (Lown et al, 1970). The dibromide (1 mmol), obtained by bromine addition to the double bond, was easily converted into the corresponding aziridine (70% yield) at room temperature by treatment with cyclohexylamine (1.1 g, 11 mmol) in toluene (10 ml), giving a mixture of cis/trans aziridine derivatives in a 60:40 ratio (determined from 1 H NMR spectra of the crude product).…”

Section: Methodsmentioning

confidence: 99%

Ethyltrans-3-(2-chloro-6,7-dimethylquinolin-3-yl)-1-cyclohexylaziridine-2-carboxylate

et al. 2007

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The molecule of the title compound, C22H27ClN2O2, contains a quinolyl unit linked to a functionalized aziridine system with a 2,3‐trans arrangement of the substituents. The cyclohexyl ring adopts a chair conformation. The aziridine plane forms a dihedral angle of 51.23 (6)° with the 2‐chloropyridine ring of the 2‐chloro‐6,7‐dimethylquinolyl group. The molecular structure is stabilized by intramolecular C—H⋯O hydrogen bonds.

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Synthesis and cycloaddition reactions of 2-(2-thienyl)aziridines

Abstract: The synthesis of several new 2-(2-thieny1)aziridines and an examination of their cycloaddition with olefinic and acetylenic dipolarophiles is described.

Cited by 26 publications

References 16 publications

1,3-Dipolar cycloaddition reactions of 2-(2′-thienyl)aziridines

1,3-Dipolar cycloaddition reactions of 2-(2′-thienyl)aziridines

Reactions of Carbonyl Ylides

Ethyltrans-3-(2-chloro-6,7-dimethylquinolin-3-yl)-1-cyclohexylaziridine-2-carboxylate

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