Synthesis of Imines From N‐(1‐Halogenoalkyl)Heteroarylium Salts

Maquestiau, A.; Anders, Ernst; Eynde, Jean Jacques Vanden; D'Orazio, Patrizia; Mayence, Annie

doi:10.1002/bscb.19890980803

Cited by 17 publications

(3 citation statements)

References 8 publications

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“…Aldehydes are known to react with N,N'-dimethyl-and N,N'-diphenyl-1,2-ethanediamines to yield imidazolidines. ', In our hands N-(1-chloroalky1)pyridinium chlorides la-h behave similarly and imidazolidines [4][5][6][7][8][9][10][11][12] (Table) were isolated in good yields. Optimalization of the experimental conditions was achieved on the basis of the nmr data.…”

Section: Resultsmentioning

confidence: 62%

Novel Syntheses of Heterocycles with N‐(1‐Haloalkyl)Azinium Halides Part 1. Preparation of Imidazolidines

Eynde

Mayence

Maquestiau

et al. 1992

Bulletin des Soc Chimique

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N-(1-Chloroalky1)pyridinium chlorides, prepared from thionyl chloride, pyridine, and an aldehyde, readily react with N,N'-disubstituted 1,2-ethanediamine to yield imidazolidines under mild and neutral conditions. N-[Chloro(2-chlorophenyl)methyl]pyridinium chloride (lc; not isolated) nmr (CH,Cl,poorly soluble): 9.7 (d, 2H, H2 and Hb pyr); 9.1-8.4 (c, 7H) ppm.N-[Chloro(4-methoxyphenyl)methyl]pyridinium chloride (la; not isolated) nmr (CH,Cl,): 9.8 (d, 2H, H2 and Hs pyr); 8.9 ( s , lH, CHC1); 8.6 (t, lH, H ' pyr); 8.2 (t, 2H, H3 and H5 pyr); 7.7 (d, 2H, H2 and H6 ph); 6.9 (d, 2H, H3 and H5 ph); 3.7 ( s , 3H, OCH,) ppm.

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Section: Resultsmentioning

confidence: 62%

Novel Syntheses of Heterocycles with N‐(1‐Haloalkyl)Azinium Halides Part 1. Preparation of Imidazolidines

Eynde

Mayence

Maquestiau

et al. 1992

Bulletin des Soc Chimique

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“…HSQC confirms that the singlet in the 1 H NMR spectrum assigned to CClH (δ 6.58 ppm) is coupled to a strongly deshielded sp 3 carbon at δ 91 ppm, which diverges substantially from both 3 a and from previously reported azaallenium complexes, instead aligning more closely with previously reported N-chloroalkylpyridinium salts. [44] Density functional theory (DFT) modeling of the azaallenium energies at the B3LYP-D3/6-311 + g(d,p)-(C,H,N,Cl)/SDD(Os)-PCM(MeCN)//B3LYP-D3/6-31g(d)-(C,H,N,Cl)/SDD(Os)-PCM(MeCN) level of theory show a stark decrease in stability of the azaallenium isomer relative to the aza-allyl chloride upon introduction of the methyl groups, presumably due to steric clashes between the methyl groups and the equatorial ligands (see Supporting Information for details).…”

Section: Methodsmentioning

confidence: 99%

A Synthetic Cycle for Heteroarene Synthesis by Nitride Insertion**

2022

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cis-terpyOsNCl2]PF6 inserts nitrogen into indenes to afford isoquinolines. The insertion proceeds through an azaallenium intermediate, with mechanistic and computational studies suggesting that azaallenium formation occurs via a stepwise aziridination followed by electrocyclic ring opening. Examination of a substrate diverted from aromatization resulted in inner-sphere ligand rearrangement to afford an azaallyl chloride complex; kinetic studies suggest this species forms via an analogous azaallenium intermediate. Studies on base-promoted release of the isoquinoline suggest that the azaallyl chloride is not an obligate intermediate for aromatization and the parent azaallenium can directly eliminate to give a neutral dichloroosmium(II)-isoquinoline intermediate. The heteroarene can subsequently be thermally liberated to afford an osmium(II) acetonitrile complex, which can be oxidized to regenerate the nitride over two steps. First, in the presence of ammonia, oxidation affords an osmium(III) amidine, with subsequent oxidation in the presence of toluene sulfonic acid ultimately regenerating the nitride. The mechanistic foundation set by this synthetic cycle opens the door to the further development of nitrogen insertion heteroarene syntheses promoted by late transition metal nitrides.

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“…Indeed preparation of 13-imidazopyridines, which are known to be potent cardiotonic agents,'& often requires drastic conditions like prolonged heating in polyphosphoric acid. ", *'Thus, we found that treatment of 4-methylbenzaldehyde with a mixture of thionyl chloride and pyridine in dichloromethane, followed by reaction with 2,3-pyridinediamine (three equivalents) produced 3-[(4-methylphenyl)-methylene1amin0-2-pyridineamine(5). We reasonedthat experimental conditions were too mild to effect the conversion of the imine into the imidazopyridine system.…”

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confidence: 99%