33797-51-2Relevant articles and documents
Preparation, Structure and Vibrational Spectrum of the Dimethylmethyleniminium Ion, including the Role of Cationic Polymers in its Formation
Clark, George R.,Shaw, Graeme L.,Surman, Peter W. J.,Taylor, Michael J.,Steele, Derek
, p. 3139 - 3144 (1994)
Crystalline X (1X, where X = Br or I) results from the reaction of N,N,N',N'-tetramethylmethylenediamine with CH2Br2 or CH2I2 at room temperature.The structure of 1Br has been determined by X-ray crystallography.The crystals are orthorhombic, a = 6.262(2) Angstroem, b = 7.428(3) Angstroem, c = 5.651(2) Angstroem, z = 2, space group Pmmn.The final R = 0.037 for 484 observed reflections.The dimethylmethyleniminium cation, 1, has crystallographically imposed mm2 symmetry, with the C=N bond distance 1.263(5) Angstroem, C-N bond distance 1.474(4) Angstroem and CH3-N-CH3 angle 114.4(4) deg.The Raman spectrum of 1, investigated as the bromide and iodide salts, and supplemented by IR data for (1)2SnBr6, has been fully assigned with the aid of ab initio calculations using the 3-21G** basis at the SCF and MP2 levels.Isotopic labelling experiments which generate (+) from CD2I2 have been used in conjuction with NMR and Raman measurements to investigate the reactions leading to the iminium salt.The intermediate (+) and a cationic polymer (n+) are implicated in the reactions which form the basis of the synthesis of I.
A Simple and Highly Diastereoselective One-Pot Synthesis of Mannich-Bases
Arend, Michael,Risch, Nikolaus
, p. 974 - 976 (2007/10/03)
A convenient one-pot procedure for the synthesis of β-amino ketones 5 from economical shelf reagents is described. Iminium salts 3 are generated in virtually quantitative yields from secondary amines 1 and aldehydes 2 mediated by NaI/Me3SiCl/NEt3. Subsequently, the salts 3 are used for the in situ aminoalkylation of enamines 4. The method provides the Mannich bases 5 in high yields and excellent diastereoselectivities (>96 % ds). It can also be applied for the aminoalkylation of other nucleophiles such as imines or electron-rich aromatic compounds.
N- AMINES AND AMIDES IN THE SYNTHESIS OF β-AMINO AND β-AMIDO KETONES
Kozyukov, V. P.,Kozyukov, Vik. P.,Mironov, V. F.
, p. 414 - 415 (2007/10/02)
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