Trimerization of Benzonitrile with Sodium

Ritter, John J.; Anderson, Richard D.

doi:10.1021/jo01084a015

Cited by 14 publications

(3 citation statements)

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“…The key step is the slow liberation of benzonitrile from the N , N ‘-bis(trimethylsilyl)benzamidinate anion in order to prevent the polymerization of the nitrile. The mechanism can be explained similar to the reaction of phenylsodium with benzonitrile which was reported several decades ago. , In agreement with these reports, the first reaction step could be the addition of the Ca−C Ph bond to the nitrile function, yielding a diphenylimide as shown in eq 3, whereas a reaction of the Ca−N bond with the nitrile function was not observed. Thereafter, two additional nitrile molecules could insert into the Ca−N bond.…”

Section: Resultssupporting

confidence: 83%

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

2007

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The metathesis reactions of (thf)4Ca(Ph)I with the corresponding potassium compounds KR yield the heteroleptic arylcalcium derivatives (thf)3Ca(Ph)[N(SiMe3)2] (1) and (thf)4Ca(Ph)PPh2 (2), due to the insolubility of KI in common organic solvents. However, the reaction of KCp and KOC6H2-2,6-tBu-4-Me with (thf)4Ca(Ph)I give the homoleptic compounds (thf)2CaCp2 (3) and (dme)CaCp2 (4) (depending on the solvent) as well as (thf)3Ca(OC6H2-2,6-tBu-4-Me)2 (5). Diphenylcalcium decomposed under these reaction conditions. The reaction of K[(Me3SiN)2CPh] with (thf)4Ca(Ph)I yields [{(thf)3Ca}2{4,4-Ph2-2,6-(C6H4)2C3N3}(μ-I)] (6). This dihydrotriazine derivative forms due to a slow liberation of benzonitrile from the starting N,N'-bis(trimethylsilyl)benzamidinate. A solvent change in order to shift the Schlenk equilibrium (2 PhCaICaPh2 + CaI2) toward the homoleptic diphenylcalcium leads immediately to ether cleavage reactions and the formation of [{(Et2O)CaPh2}4·(Et2O)CaO] (7), which precipitates from diethyl ether. This cage compound contains an oxygen-centered Ca5 square pyramid with the phenyl groups bridging all Ca···Ca edges.

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Section: Resultssupporting

confidence: 83%

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

2007

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“…53 Dihydrotriazines are commonly prepared by (i) acidcatalyzed cyclocondensation between biguanidines, [35][36][37][38][54][55][56] cyanoguanidines, amines, 40,45,48,50,[56][57][58] N′-amidinothioureas, 55 and carbonyl compounds, (ii) cyclocondensation of RCN with carbonyl compound and NH 3 in alcohols under harsh conditions, 59,60 (iii) cyclization of thiourea derivative 52 or polymer-bound guanidines (solid-phase synthesis) 61 with chlorcarbonylisocyanate and cyclization of two N′-(aminocarbonyl)imidocarbamates, 62 (iv) cyclization of imidothiocarbamate derivative 63 or guanidine 64 with isothiocyanate derivative and cyclization of amidines with imidoylisothiocyanates, 65 and (v) trimerization of RCN induced by alkyllithium derivatives 66 or sodium. 67 Hence, the [4 + 2]-cycloaddition of 1,3-diaza-1,3-diene to carbodiimides, described in this section, constitutes a novel synthetic approach to this useful class of heterocyclic species.…”

Section: Resultsmentioning

confidence: 99%

Pt^II-Mediated Nitrile−Tetramethylguanidine Coupling as a Key Step for a Novel Synthesis of 1,6-Dihydro-1,3,5-triazines

et al. 2007

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The coupling between tetramethylguanidine, HN=C(NMe2)2, and coordinated organonitriles in the platinum(II) complexes cis/trans-[PtCl2(RCN)2] (R = Me, Et, Ph) proceeds rapidly under mild conditions to afford the diimino compounds containing two N-bound monodentate 1,3-diaza-1,3-diene ligands [PtCl2{NH=C(R)N=C(NMe2)2}2] (R = Et, trans-1; R = Ph, trans-2; R = Me, cis-3; R = Et, cis-4), and this reaction is the first observation of metal-mediated nucleophilic addition of a guanidine to ligated nitrile. Complexes 1-4 were characterized by elemental analyses (C, H, N), X-ray diffraction, FAB mass spectrometry, IR, and 1H and 13C{1H} NMR spectroscopies; assignment of signals from E/Z-forms of 1,3-diaza-1,3-diene ligands and verification of routes for their Z right harpoon over left harpoon E isomerization in solution were performed using 2D 1H,1H-COSY, 1H,13C-HETCOR, and 1D NOE NMR experiments. The newly formed and previously unknown 1,3-diaza-1,3-dienes NH=C(R)N=C(NMe2)2 were liberated from the platinum(II) complexes [PtCl2{NH=C(R)N=C(NMe2)2}2] (1-3) by substitution with 2 equiv of 1,2-bis-(diphenylphosphino)ethane (dppe) to give the uncomplexed HN=C(R)N=C(NMe2)2 species (5-7) in solution and the solid [Pt(dppe)2](Cl)2. The former were utilized in situ, after filtration of the latter, in the reaction with 1,3-di-p-tolylcarbodiimide, (p-tol)N=C=N(tol-p), in CDCl3 to generate (6E)-N,N-dimethyl-1-(4-methylphenyl)-6-[(4-methylphenyl)imino]-1,6-dihydro-1,3,5-triazin-2-amines) (8-10) due to the [4 + 2]-cycloaddition accompanying elimination of HNMe2. The formulation of 8-10 is based on ESI-MS, 1H, 13C{1H} NMR, and X-ray crystal structures determined for 9 and 10. The reaction of 1,3-diaza-1,3-dienes with 1,3-di-p-tolylcarbodiimide, described in this article, constitutes a novel synthetic approach to a useful class of heterocyclic species like 1,6-dihydro-1,3,5-triazines.

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“…According to the in situ NMR spectra, pyridines were formed in the reaction process, which indicates that product 10 is an organolithium compound. Quenching of 10 afforded triazine 3a as the only organic product . On the basis of all these observations, the structures of 10 are proposed and shown in Scheme .…”

Section: Resultsmentioning

confidence: 95%

DFT Studies on the Reaction Mechanisms of 1,4-Dilithio 1,3-Dienes with Nitriles

et al. 2013

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Mechanisms for the reactions of 1,4-dilithio-1,3-butadienes and nitriles are explored through both experiments and DFT calculations. The computational results suggest that the selectivity of these reaction systems is strongly affected by the structures of the substrates. As the first step of all reaction pathways, the addition intermediate of one C−Li bond to the nitrile is formed. When tetraalkyl-substituted 1,4dilithio 1,3-dienes and 2-cyanopyridine are used, the intermediate gives the cyclopentadienyl amine product as the kinetic product because of the coordination of the pyridyl N atom to the lithium atoms (system B). This addition intermediate also undergoes a second nitrile insertion into the C−Li bond, giving the dilithio ketimine intermediate. When tetraalkyl-substituted 1,4-dilithio 1,3-dienes and aryl nitriles are used, the dilithio ketimine intermediate undergoes a 1,6-cyclization, generating pyridine and triazine products through thermodynamically favored pathways (systems A and B). When cyclic 1,4-dilithiobutadiene and tertiary aliphatic nitriles are used, the dilithio ketimine intermediate undergoes two sequential 1,5-cyclization steps with a lower energy barrier, generating tricyclic Δ 1 -bipyrrolines (system C). Experimentally, the lithium-containing triazine intermediate 10 and Δ 1 -bipyrroline intermediate 19 have been isolated and their structures investigated through NMR and quenching experiments. The calculation results clearly show the mechanism details of these reactions and are in good agreement with the experimental observations.

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Trimerization of Benzonitrile with Sodium

Cited by 14 publications

References 1 publication

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

Pt^II-Mediated Nitrile−Tetramethylguanidine Coupling as a Key Step for a Novel Synthesis of 1,6-Dihydro-1,3,5-triazines

DFT Studies on the Reaction Mechanisms of 1,4-Dilithio 1,3-Dienes with Nitriles

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Trimerization of Benzonitrile with Sodium

Cited by 14 publications

References 1 publication

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)4I with Potassium Compounds

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)4I with Potassium Compounds

PtII-Mediated Nitrile−Tetramethylguanidine Coupling as a Key Step for a Novel Synthesis of 1,6-Dihydro-1,3,5-triazines

DFT Studies on the Reaction Mechanisms of 1,4-Dilithio 1,3-Dienes with Nitriles

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Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

Heteroleptic Phenylcalcium Derivatives via Metathesis Reactions of PhCa(thf)₄I with Potassium Compounds

Pt^II-Mediated Nitrile−Tetramethylguanidine Coupling as a Key Step for a Novel Synthesis of 1,6-Dihydro-1,3,5-triazines