Mechanistic diagnosis of aminium salt initiated Diels-Alder cycloadditions in the diene/diene format

Reynolds, Dan W.; Lorenz, Kurt; Chiou, Huh Sun; Bellville, Dennis J.; Pabon, Raul; Bauld, Nathan L.

doi:10.1021/ja00250a033

Cited by 74 publications

(27 citation statements)

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“…[13] When this test was applied to the aminium hexachloroantimonate-induced reactions of 1aϪi, we found that DBP, added either in equimolar quantities or in a slight excess vs. the catalyst, inhibited the cyclodimerization giving rise to the formation of a dusty white precipitate and a fading of the solutions. Inhibition and formation of the white precipitate were also observed in the presence of SbCl 5 .…”

Section: Resultsmentioning

confidence: 99%

Acid Catalysis in the Aminium Hexachloroantimonate-Induced Cyclodimerization of 1-Aryl-1-phenylethylenes

et al. 2002

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Section: Resultsmentioning

confidence: 99%

Acid Catalysis in the Aminium Hexachloroantimonate-Induced Cyclodimerization of 1-Aryl-1-phenylethylenes

et al. 2002

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“…The adduct 3a has previously been obtained in 75% yield as a 4 : 1 mixture of the endo-and exo-trans-diastereoisomers. [8] The purified endo-isomer, obtained by silica gel chromatography using a petroleum ether eluent, was used for the polymerization studies. Polymerization using the Grubbs catalyst [bis(tricyclohexylphosphine)benzylidine…”

Section: Resultsmentioning

confidence: 99%

An Efficient Synthesis of Ring-Opening Metathesis Monomers and Polymers Containing Carbazole and Other Electron-Rich Moieties

2001

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“…idine as a base. [35] The reaction is also very efficiently catalyzed by photoinduced ET with tris(anisylpyrrylium) tetrafluoroborate as the sensitizer, which does not contain the traces of acids often found as impurities in amminium salts. Further control experiments showed that the efficient [22] retrocyclization of 1 under these conditions does not result from a direct photoreaction of neutral 1 or weak Lewis acid properties of the pyrrylium salt.…”

Section: Methodsmentioning

confidence: 99%

Ion Chemistry of anti-o,o′-Dibenzene

et al. 2000

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The ion chemistry of anti-o,o'-dibenzene (1) was examined in the gaseous and the condensed phase. From a series of comparative ion cyclotron resonance (ICR) mass spectrometry experiments which involved the interaction of Cu+ with 1, benzene, or mixtures of both, it was demonstrated that 1 can be brought into the gas phase as an intact molecule under the experimental conditions employed. The molecular ions, formally 1*+ and 1*- , were investigated with a four-sector mass spectrometer in metastable-ion decay, collisional activation, charge reversal, and neutralization-reionization experiments. Surprisingly, the expected retrocyclization to yield two benzene molecules was not dominant for the long-lived molecular ions; however, other fragmentations, such as methyl and hydrogen losses, prevailed. In contrast, matrix ionization of 1 in freon (77 K) by gamma-radiation or in argon (12 K) by X-irradiation leads to quantitative retrocyclization to the cationic dimer of benzene, 2*+. Theoretical modeling of the potential-energy surface for the retrocyclization shows that only a small, if any, activation barrier is to be expected for this process. In another series of experiments, metal complexes of 1 were investigated. 1/Cr+ was formed in the ion source and examined by metastable ion decay and collisional activation experiments, which revealed predominant losses of neutral benzene. Nevertheless, comparison with the bis-ligated [(C6H6)2Cr]+ complex provided evidence for the existence of an intact 1/Cr+ under these experimental conditions. No evidence for the existence of 1/Fe+ was obtained, which suggests that iron mediates the rapid retrocyclization of 1/Fe+ into the bis-ligated benzene complex [(C6H6)2Fe]+.

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Mechanistic diagnosis of aminium salt initiated Diels-Alder cycloadditions in the diene/diene format

Cited by 74 publications

References 0 publications

Acid Catalysis in the Aminium Hexachloroantimonate-Induced Cyclodimerization of 1-Aryl-1-phenylethylenes

Acid Catalysis in the Aminium Hexachloroantimonate-Induced Cyclodimerization of 1-Aryl-1-phenylethylenes

An Efficient Synthesis of Ring-Opening Metathesis Monomers and Polymers Containing Carbazole and Other Electron-Rich Moieties

Ion Chemistry of anti-o,o′-Dibenzene

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