Synthesis of Oxazoles by the Reaction of Ketones with …

the importance because it synthesize high yield of amino esters and amino ketones
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Synthesis of Substituted Imidazoles via Organocatalysis …

These compounds were synthesized from cyclic ketones involving reduction of the ketone cyanohydrins and reaction of the resultant 2-hydroxyethylamines with CNBr. The effect of CNS activity was evaluated by the observation of albino Swiss-Webster mice for gross changes in behavior.

A method and apparatus for the production of ketones via a one-step synthesis from aldehydes
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Synthesis of Substituted Imidazoles via Organocatalysis Doug E

Wehypothesized that activation of an aldehyde/ketone in the form of an enamineintermediate could preclude alkyne–metal binding and activation, since weexpect that enamines could be excellent ligands for the pi-acid metals ofinterest under typical intermolecular conditions.

a novel method for the synthesis of oxazole derivatives from methyl ketones and benzoins.
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p-Toluenesulfonylmethyl isocyanide (TosMIC) is one of the most versatile and widely applicable reagents in organic synthesis. The methylene group of TosMIC is highly activated (pKa = 14) by the two electron-withdrawing substituents. Deprotonation of TosMIC has been achieved with an array of bases ranging from K2CO3 in MeOH to n-BuLi in THF. TosMIC is considered as a formaldehyde equivalent with reversible polarity. The reagent is a stable solid (mp 116-117 °C) that is commercially available, or can be prepared from p-toluenesulfonic acid [] in a two-step process. Many heterocycles, such as oxazole, pyrrole, ­imidazole, thiazole and 1,3,4-triazole, can be synthesized from TosMIC.

Designing Organic Syntheses Syntheseplanung …
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doi:10.1021/jo00170a070 - ACS Publications Home Page

Preliminarystudies for intermolecular additions of aldehydes/ketones to alkynes Dualcatalyst systems (amines together with transition metals and ligands) have beenused to promote intramolecular additions of aldehydes/ketones to unactivatedalkynes (i.e.

Aerobic Copper-Catalyzed Organic Reactions - …

To explore the feasibility of new catalysts for theintermolecular direct addition of aldehydes/ketones to alkynes, we havedeveloped a computational chemistry workflow whereby putative catalystintermediates are optimized by DFT before and after carbon–carbon bondformation, and the Gibbs free energy is calculated for each, with theassumption that a working catalyst must have an exergonic C–C bondformation step.

Allen was born in 1984 in Kutztown, Pennsylvania

Abstracts (A) Most ketones are converted in one operation into cyanides with TosMIC in the presence of potassium tert-butoxide in non-protic solvents (DME, DMSO).2 The reductive cyanation of some aldehyde3 was carried out at low temperature and needs addition of methanol. (B) TosMIC on reaction with aldehyde in methanol at room ­temperature leads to oxazolene, where as oxazoles were formed at reflux temperature.4 The addition of TosMIC to the aldehyde is ­followed by cyclization and subsequent elimination of the tosyl group to afford oxazole. Dhar et al. reported a modified oxazole synthesis using DBU in DME at 80 °C.4b (C) Base-induced addition of TosMIC to aldimines in protic medium occurs with concomitant cyclization followed by elimination of p-toluenesulfonic acid to result in imidazoles.5 (D) Pyrroles6 are obtained by base-induced addition of TosMIC to Michael acceptors. The ring closure between the isocyano and ­enolate carbons is followed by aromatization. (E) TosMIC, on reaction with diazonium salts, results in 1,2,4-triazoles.7 The TosMIC anion attacks the electrophilic b-nitrogen of the diazonium ion, then ring closure occurs. (F) Mono- and dialkylated TosMIC8 were formed from corresponding alkyl halides under phase transfer conditions. Hydrolysis of dialkylated TosMIC leads to symmetrical and unsymmetrical ketones.9 The reduction of mono and dialkylated TosMIC with Li in liquid NH3 afforded the corresponding hydrocarbons.10 (G) Reaction of TosMIC with carbondisulfides under phase transfer conditions provides the tetrabutylammonium salt of thiazole, which can be converted to thiazole.11 (H) Recently, the synthesis of C-nucleosides by the TosMIC approach from sugar-derived aldehydes and other Michael acceptors was reported.12

PDF Downloads : Oriental Journal of Chemistry

Synthesis of - and -likeprecatalysts Wehave completed the synthesis of several - and -like precatalysts, with a representative exampledepicted in Fig.