77767-52-3Relevant academic research and scientific papers
Cycloaddition Reactions of Heterocumulenes, XXIII.- Nitrogen-Containing Five-Membered Heterocycles from Carbodiimides or Ketenimines with 3-Dimethylamino-2H-azirines
Schaumann, Ernst,Grabley, Susanne
, p. 290 - 305 (2007/10/02)
Depending on the substituents, carbodiimides 1 effect 1,2 or 1,3 ring-opening of aminoazirines 2; alkyl(sulfonyl)carbodiimides 1b-d can enter into the cycloaddition via either C=N bond.Thus, starting from diphenylcarbodiimide (1a) or the sulfonylcarbodiimides 1c, d, the zwitterions 5 are formed by cleavage of C=N in 2; the reduction, hydrolysis, thiolysis, or aminolysis of which yields imidazolidines 7-9, 15.With methyl iodide, 5a, b are alkylated non-specifically either at the endo- or exo-cyclic nitrogen of the anion moiety.In the reactions of 1c and d with 2 1,2-competes with 1,3-bond cleavage and leads to acrylamidines 17d-g as well as imidazolines 18d, 19c.For mesyl(methyl)carbodiimide (1b), 1,2 ring-opening is observed exclusively affording 17a-c besides 19a, b.Similarly, in the cycloaddition of ketenimines 23a, b with azirine 2b only 1,2-bond cleavage can be detected to give pyrrolines 26a, b and imidazole derivatives 28, respectively.
