Nitrogen Analogs of Sesquifulvalene. I. Synthesis and Properties<sup>1a,2</sup>

Berson, Jerome A.; Evleth, E. M.; Hamlet, Z.

doi:10.1021/ja01091a019

Cited by 41 publications

(8 citation statements)

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“…The chloride salt was multiply recrystallized from acetonitrile and then metathesized in aqueous solutions containing alkali salts of the desired anions. Tetrafluoroborates of 2 and 3 (MeImCH 2 ArOH + and PyCH 2 ArOH + , respectively) were synthesized from pyridinium (- h 5 or - d 5 ) and 1-methylimidazolium tetrafluoroborates and 3,5-di- tert- butyl-4-hydroxybenzyl alcohol in the Mitsunobu reaction. , Cation 4 was obtained by quaternization of diphenyl-4-pyridylmethane. , All of the ionic compounds were crystalline, including the bistriflimides (e.g., see the crystal structure for 1b NTf 2 in section 2S and Figure 1S, Supporting Information). This allowed us to achieve high purity through the use of multiple recrystallization.…”

Section: Experimental and Computational Methodsmentioning

confidence: 99%

Radiation Stability of Cations in Ionic Liquids. 4. Task-Specific Antioxidant Cations for Nuclear Separations and Photolithography

Shkrob

Marin

2013

J. Phys. Chem. B

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Three families of "task-specific" antioxidant organic cations that include designated sites to facilitate deprotonation following electronic excitation and ionization have been introduced. The deprotonation from the excited state is reversible, leading to minimal damage of the cation, whereas the deprotonation from the oxidized cation yields persistent aroxyl and trityl radicals. This protection improves radiation stability of ionic compounds in 2.5 MeV electron beam radiolysis. Apart from the use of such cations as structural components of room temperature ionic liquid (IL) diluents for nuclear separations, their ionic compounds involving bases of superacids are well suited for use as chemically amplified acid generator resists in electron beam lithography and extreme ultraviolet photolithography.

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Section: Experimental and Computational Methodsmentioning

confidence: 99%

Radiation Stability of Cations in Ionic Liquids. 4. Task-Specific Antioxidant Cations for Nuclear Separations and Photolithography

Shkrob

Marin

2013

J. Phys. Chem. B

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“…(33) Preparation of 7V-methyl-2-cyclopentadienylidene-1,2-dihydropyridine from cyclopentadienylsodium and 2-iodopyridine methiodide [197].…”

Section: -7 Reduction Of L-methyl-l 9 234-tetrahydroquinoline To mentioning

confidence: 99%

Enamines

1971

Organic Chemistry: A Series of Monographs

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The chemistry of enamines has been described in several reviews [25][26][27][28][29] and in a recent monograph [30]. CONDENSATION REACTIONS A. Condensation of Secondary Amines with Aldehydes and KetonesThe most widely used method for preparing enamines involves the conden sation of aldehydes and ketones with secondary amines (Eq. 6). In 1936, Mannich and Davidsen [31] were the first to describe the reaction of secondary amines with aldehydes in the presence of anhydrous potassium carbonate at approximately 0°C to give enamines (Eqs. 6, 7). R-CH 2 CH=0 + 2HNR , R-C-CH R' + HNRJ II oMannich and Davidsen [31] also reported that most of the aldehydes were first converted to a diamino intermediate which on distillation afforded the enamine. Less successful was the attempt to extend the reaction to ketones. Only with the use of calcium oxide at elevated temperatures were the enamines directly obtained, but in poor yields. Herr and Heyl [32,33] found that better yields of enamines from ketones can be obtained by the azeotropic removal of water in the presence or absence [32,33] of acid catalysts [12a, b, 34, 35]

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“…227, 245, 246). Some other methods employed for the synthesis of compounds of these series deserve a brief mention (49): cyclopentadienylsodium gave, with compounds such as 2-halo-l-methylor -1-benzylpyridinium halides (XLVI), the heterosubstituted fulvenes XLVII, with liberation of 1 mole of cyclopentadiene. Cyclopent-2en-l-one and 2-pyridyllithium afforded the tertiary alcohol XLVIII, the methosulfate of which gave by successive treatment with acid and alkali the fulvene XLVII (R = CH3).…”

Section: O-+ Omentioning

confidence: 99%

“…It can be assumed that the reaction of CXXXIII with lithium alkyls also proceeds via an intermediate of formula CD. In a more complex representative of this class, N-methyl-2cyclopentadienylidene-l,2-dihydropyridine (XXIII), lithium aluminum hydride reduces first one of the double bonds of the pyridine moiety, giving a product like GDI, and only then attacks the fulvenic bond (49). Compound XXIII is protonated on a carbon, and not on the nitrogen atom; its solution in trifluoroacetic acid contains both ions CDII and CDIII (49).…”

Section: Miscellaneous Addition Reactionsmentioning

confidence: 99%