ChemInform Abstract: UEBER DAS 1‐METHYL‐PHTHALAZINIUM‐CARBAETHOXYMETHYL‐YLID 3. MITT.

Abstract

Das Phthalazin (I) kann mit Bromessigester (II) zum Phthalaziniumsalz (III) quaterniert werden.

4-(4-Chloro-phenyl)-pyrimidinium ylides. 1. Structure, stability, reactivity

“…The difference ν C=O salt -ν C=O ylide = 34 cm -1 is in accordance with the delocalization phenomena of the negative charge from the ylide carbanion to the phenyl ring ( Figure 2) and confirms our previous supposition. The 1 H NMR of ylide 5c confirms also the structure. Thus, at 10.75 ppm appears the signal of H-2 α-endocyclic hydrogen atom (singlet).…”

“…According to the literature indications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] the chemistry of cycloiminium ylides is widely discussed. In previous research work we have studied the synthesis, structure, and reactivity of some 1,2-diazinium ylides [12][13][14] (derived from pyridazine and phthalazine) as well as of 1,3-diazinium ylides [15][16][17] (derived from 4-methylpyrimidine).…”

New N-bridgehead heterocyclic compounds. II. Carbamoyl-substituted azaindolizines

“…4,5 Intermediate diazinium N-carbamoylmethylides were obtained by the dehydrohalogenation of the corresponding N-phenylcarbamoylmethyl diazinium quaternary salts. By the direct reactions of the pyridazine and 4-substituted pyrimidines with bromo acetanilides the corresponding N-phenylcarbamoylmethyl quaternary salts 1-7 were obtained (Scheme 1, Table 1).…”

Structure, liquid and solid state synthesis for dimers via [3+3] dipolar cycloadditions

“…According to the literature, [1][2][3][4][5][6][7][8][9][10][11] the chemistry of cycloimmonium ylides is widely discussed, either because of their theoretical importance [1][2][3][4][5][6][7] ]. In most cases, the ylides react with a large variety of dipolarophiles (with double or triple bonds) via a [3+2] dipolar cycloaddition.…”

“…Depending on the reactivity and stability of ylides, an undesirable competitive [3+3] dipolar cycloaddition of two molecules of the ylide can take place, leading to dimers. [1][2][3] The structures of these dimers were often established only through IR, UV-VIS or 60-80 MHz 1 H-NMR spectra and, accordingly, may be uncertain. 1-3, 16, 19 Further, classical heating was employed for the reported cycloadditions; however, in recent years, microwave heating [12][13][14][15]17 has become a versatile alternative to classical heating.…”