40114-95-2

Upstream product

• 123-91-1 1,4-dioxane 
• 100-48-1 pyridine-4-carbonitrile 
• 108-85-0 1-bromocyclohexane 
• 110-82-7 cyclohexane 
• 626-62-0 Cyclohexyl iodide 
• 41320-40-5 <<(methylthio)thiocarbonyl>oxy>cyclohexane 
• 14906-59-3 4-cyanopyridine N-oxide 
• 51342-23-5 N-methoxy-4-cyanopyridinium methylsulfate 
• 98-89-5 Cyclohexanecarboxylic acid 

Relevant academic research and scientific papers

Visible-Light-Mediated C-H Alkylation of Pyridine Derivatives

We report herein a visible-light-mediated C-H alkylation of pyridine derivatives that proceeds by simple combination of a large variety of N-alkoxypyridinium ions with alkanes in the presence of 2 mol % of fac-Ir(ppy)3 under blue illumination. The mild reaction conditions together with the high group functional tolerance make of this process a useful synthetic platform for the construction of structurally strained heterocycles. Detailed mechanistic investigations, including density functional theory calculations and quantum yield measurement, allowed us to understand factors controlling the reactivity and the selectivity of the reaction.

Copper catalytic N - heterocycle aromatic hydrocarbon compound C (sp2 ) - H key alkylation method

The invention discloses a copper-catalyticN -Heterocycle aromatic hydrocarbon compound C (sp2 ) Alkylation method - H of the key, the method is as follows: in the copper salt, N - F reagent, proton acid and under the action of the organic solvent,N -Heterocycle aromatic hydrocarbon compounds and a naphthenic hydrocarbon compound or [...] compounds alkylation reaction, the reaction temperature is 20 - 60 °C, the reaction time is 3 - 20 h, after the reaction, the reaction solution obtained after treatmentN- Heterocycle aromatic hydrocarbon derivatives. This invention utilizes the copper catalytic realizeN -Heterocycle aromatic hydrocarbon compounds and a [...] compound or naphthenic hydrocarbon compounds of the CDC reaction, the invention expands the scope of application of the reaction substrate, quinoline derivatives, pyridine derivatives, isoquinoline derivatives, BENZOXAZOL derivatives, benzothiazole derivatives such as aromatic nitrogen containing compounds are all using this method for carrying out the alkylation.

Transition-metal-free cross-dehydrogenative alkylation of pyridines under neutral conditions

A mild and efficient method has been developed for the direct dehydrogenative alkylation of unprotonated pyridine derivatives. The avoidance of using acids and transition-metals makes this protocol greener and more practical for the synthesis of substituted pyridines.

Polar Effects in Free-Radical Reactions. Homolytic Heteroaromatic Substitutions by Alkyl Bromides

Alkyl bromides have been utilized for the first time as radical sources for heteroaromatic substitution.A variety of procedures was revealed to be successful for bromine abstraction: Bu3SnH with AIBN, (Me3Si)3SiH with AIBN, Ph2SiH2, or Et3SiH associated with peroxides (H2O2, t-BuOOH, (t-BuO)2, (t-BuOOCO)2, (PhCOO)2).The importance of the polar effects is discussed.

A novel radical reaction of alkyl xantates useful for the selective substitution of heteroaromatic bases

Cyclohexyl radical is generated from cyclohexyldithiocarbonate and benzoyl peroxide. The radical source is used for the alkylation of heteroaromatic bases.

Homolytic alkylation of heteroaromatic bases : The problem of monoalkylation

The silver-catalyzed decarboxylation of carboxylic acids by persulphate leads to alkyl radicals, which have been utilized for the selective alkylation of heteroaromatic bases. The method is particularly efficient in a water-chlorobenzene two-phase system for two reasons : it considerably increases the selectivity in monoalkylation when more positions of high nucleophilic reactivity (i.e. α and γ) are available in the heterocyclic ring (i.e. quinoline , 4-cyano- and 4-ethylpyridine, pyrazine , quinoxaline etc.) and it determines a much higher efficiency for the radical sources when the silver salt catalysis is deactivated by complexation of the salt with the heterocyclic compound . The high selectivity in monoalkylation has been obtained by the combination of polar effects and the increased lipophilicity of the alkylated product, which makes its extraction from the aqueous solution by the organic solvent easier.

New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides

New general, selective processes of homolytic alkylation of protonated heteroaromatic bases have been developed using alkyl iodides and t-BuOOH or (t-BuO)2 as sources of alkyl radicals.Both processes are based on the generation of methyl radical from the peroxides, and on iodine abstraction from the alkyl iodide by the methyl radical.The selective processes are the result of combined enthalpic and polar effects.The enthalpic factor governs the equilibrium of iodine abstraction, whereas the polar effect governs the reactivity of the alkyl radicals with the protonated heteroaromatic ring.A redox chain is operative with t-BuOOH and an unusual free-radical chain process is involved with (t-BuO)2.Both chains are particularly effective because of the electron-transfer oxidation of the pyridyl radical intermediate, the ionization potential of which (5.4-6.0 eV) is close to that of lithium (5.39 eV) or sodium (5.14 eV).

Polar Effects in Free-Radical Reactions. Rate Constants in Phenylation and New Methods of Selective Alkylation of Heteroaromatic Bases

The rate constants for the addition of the phenyl radical to protonated and unprotonated 4-substituted pyridines have been determined by competition with chlorine abstraction from CCl4.The constants range from 2 * 105 to 6 * 106 M-1 s-1 depending on the substituent and on the degree of protonation.The phenyl radical shows a clear-cut nucleophilic character.On the basis of these rate constants, the use of phenyl radical from diazonium salt or benzoyl peroxide to generate alkyl radicals by iodine or hydrogen abstraction has been developed as a general procedure for the alkylation of heteroaromatic bases.This reaction is characterized by high yields and selectivities.

SELECTIVE SUBSTITUTION OF UNPROTONATED PYRIDINES BY ALKYL RADICALS

The reactions of dioxanyl and cyclohexyl radicals with 2- and 3-X-pyridines (X=CN, COMe, CO2Me) give a single substitution product deriving by addition at the 5- and 6-position respectively; with 4-X-pyridines substitution occurs preferentially at the 3-position.If the reactions are carried out with protonated pyridines other positional isomers are obtained.From the synthetic point of view the two procedures are therefore complementary.The change in positional selectivity on passing from unprotonated to protonated aromatic substrates is discussed and interpreted on the basis of the different nature of the transition state of the addition step.