ChemInform Abstract: Fused Quinolines with Bridgehead Nitrogen Atom.

Volovenko, Yu. M.; Nemazanyi, A. G.; Ryabokon, I. G.; Babichev, F. S.

doi:10.1002/chin.198836224

Cited by 8 publications

(7 citation statements)

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“…This bypasses the risks associated with trying to isolate “free” carbene species of an unknown type. The synthesis of a variety of 6‐hydroxy‐benzo[ c ]quinolizinium halide salts has been reported in the literature by the groups of Vierfond,22, 23 Ziegler24 and Volovenko,25, 26 and the choice of the appropriate method depends on the desired substituent pattern present on the benzo[ c ]quinolizinium frame. Initially, we followed a modification of Vierfond’s synthetic protocol (Scheme ) that enabled us to obtain 2‐(2‐chlorophenyl)acylpyridinium chloride salt ( 2 ) in high yield (81 %).…”

Section: Resultsmentioning

confidence: 99%

A New Class of Remote N‐Heterocyclic Carbenes with Exceptionally Strong σ‐Donor Properties: Introducing Benzo[c]quinolin‐6‐ylidene

Mayer

Murphy

Haddow

et al. 2013

Chemistry A European J

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We make the case for benzo[c]quinolin-6-ylidene (1) as a strongly electron-donating carbene ligand. The facile synthesis of 6-trifluoromethanesulfonylbenzo[c]quinolizinium trifluoromethanesulfonate (2) gives straightforward access to a useful precursor for oxidative addition to low-valent metals, to yield the desired carbene complexes. This concept has been achieved in the case of [Mn(benzo[c]quinolin-6-ylidene)(CO)5](+) (15) and [Pd(benzo[c]quinolin-6-ylidene)(PPh3)2(L)](2+) L = THF (21), OTf (22) or pyridine (23). Attempts to coordinate to nickel result in coupling products from two carbene precursor fragments. The CO IR-stretching-frequency data for the manganese compound suggests benzo[c]quinolin-6-ylidene is at least as strong a donor as any heteroatom-stabilised carbene ligand reported.

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Section: Resultsmentioning

confidence: 99%

A New Class of Remote N‐Heterocyclic Carbenes with Exceptionally Strong σ‐Donor Properties: Introducing Benzo[c]quinolin‐6‐ylidene

Mayer

Murphy

Haddow

et al. 2013

Chemistry A European J

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“…According to the spectral data, compounds 2a-h exist exclusively in the form of NH tautomers with an intramolecular hydrogen bond, as known for the acyl derivatives of hetarylacetonitriles [44]. Thus, the 1 H NMR spectra of the butyronitriles 2a-e…”

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confidence: 98%

Synthesis of 5-amino-4-hetaryl-2,3-dihydro-1h-3-pyrrolones

Tverdokhlebov

Lyashenko

Volovenko

et al. 2004

Chem Heterocycl Compd

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The interest in derivatives of 2-aminopyrrole has arisen in connection with their prospective use as medicines [1][2][3][4][5][6][7][8] and as components of dyes in photography [9][10][11]. The principal methods for the synthesis of these compounds are the condensation of methylene-active nitriles with derivatives of α-aminocarbonyl compounds [12][13][14][15][16][17] or amination of substituted 4-halobutyronitriles [18][19][20][21][22][23][24] or their synthetic equivalents [25][26][27]. Both approaches have been successfully applied to the synthesis of 1-R 1 -2,2-R 2 ,R 3 -5-amino-4-hetaryl-2,3-dihydro-3-pyrrolones [28][29][30][31][32][33][34][35][36][37]. However, they cannot be used for the production of similar derivatives unsubstituted at position 1 since, on the one hand, the N-unsubstituted α-aminocarbonyl compounds quickly dimerize to pyrazine derivatives and, on the other, the use of ammonia in the reaction together with the need for heat and a nonaqueous medium give rise to certain technical difficulties. For this reason we developed a different method for the synthesis of N-unsubstituted 2,3-dihydro-1H-3-pyrrolones 1a-h, and this method is described here.The key compounds in the synthesis of the dihydropyrrolones 1 are 2-hetaryl-3-oxo-4-phthalimidobutyronitriles 2a-e and the corresponding pentanonitriles 2f-h, obtained by acylation of the hetarylacetonitriles 3a-e with the chlorides of N-phthaloylglycine 4a and alanine 4b (see the scheme). It should be noted that acylation of the sodium salts of simple methylene-active compounds with the chlorides [38-41] and esters [17,42,43] of protected α-amino acids was used earlier for construction of the pyrrole ring. However, the acid chlorides often gave the products from bis-C,C-and bis-C,O-acylation [38,40] of complex mixtures [39], while the esters gave the enolates of the corresponding acyl derivatives. During transformation of the latter into the conjugate acids it was not always possible to avoid side processes associated with hydrolysis of the protecting groups [42,43]. We obtained the monoacyl derivatives 2a-h with yields of more than 90% as the only products (Scheme 1).The composition and structure of the nitriles 2a-h were confirmed by the results of elemental analysis (Table 1) and also by data from the IR and 1 H NMR spectra (Table 2). According to the spectral data, compounds 2a-h exist exclusively in the form of NH tautomers with an intramolecular hydrogen bond, as known for the acyl derivatives of hetarylacetonitriles [44]. Thus, the 1 H NMR spectra of the butyronitriles 2a-e

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“…38 1 (2,4 Difluorobenzoyl) 2 ethylisothiourea (3). Triethyl amine (2.7 mL, 19.4 mmol) and a solution of 2,4 difluorobenzoyl chloride 2 (19.6 mL, 9.7 mmol) in toluene (6 mL) were added to a stirred suspension of S ethylisothiourea hydroiodide (2.3 g, 9.7 mmol) in anhydrous CH 2 Cl 2 (20 mL).…”

Section: H Nmr Spectra Were Recorded On Bruker Wm 250 Andmentioning

confidence: 99%