119208-65-0Relevant articles and documents
2-Azaallenium Salts from N-Benzylidene-α-methoxybenzylamines
Weidner, Reinhold,Wuerthwein, Ernst-Ulrich
, p. 1095 - 1106 (2007/10/02)
New phenyl-substituted 2-azaallenium salts 1 with variable substitution pattern were synthesized in high yields and under mild reaction conditions by treatment of N-benzylidene-α-methoxy-benzylamines 4 with acylium salts.The amines 4 are easily accessible from imines 2 and α-chloro ethers 3 or from 2,4-diaza-1,4-pentadiones 7; only in the case of strong steric hindrance an alternate reaction (forming imidazole 6) takes place.Some of the new 2-azaallenium salts (1ea-1ed, 1fa-1fd) show high tendency for intramolecular cyclisation reactions leading to isoquinoline derivatives 8 and 9. - The structures of the salts 1 in solution were analysed on the basis of 1H- and 13C-NMR spectra with respect to the dynamic behaviour of the cations.For 1aa-1j cumulene structures were derived, for the intensively coloured 1k, however, a 2-azaallyl cation structure of the aza-trimethine dyestuff type was found (IR data). - Keywords: 2-Azaallenium Salts; N-Benzylidene-α-methoxybenzylamines
