19233-44-4

Upstream product

• 63017-05-0 2-bromo-2-chloropropiophenone 
• 124-41-4 sodium methylate 
• 6125-76-4 cyclohexyl-(1-phenyl-propylidene)-amine 
• 56-23-5 tetrachloromethane 
• 13735-81-4 1-styrenyloxytrimethylsilane 
• 18624-83-4 2,2-Dichloro-2-methylsulfanyl-1-phenyl-ethanone 
• 78102-52-0 cis-2,3-Dichlor-2-methyl-3-phenyloxiran 
• 768-03-6 Phenyl vinyl ketone 
• 50-00-0 formaldehyd 
• 532-27-4 1-chloroacetophenone 
• 4393-06-0 1-Phenyl-2-propen-1-ol 
• 104755-22-8 C₁₅H₁₄Cl₂OSe 
• 93-55-0 1-phenyl-propan-1-one 
• 5398-93-6 2-methylthio-1-phenyl-ethanone 

Downstream Products

• 6084-17-9 2-chloro-1-phenylpropan-1-one 
• 143427-03-6 2-Chloro-1-phenyl-heptan-1-one 

Relevant academic research and scientific papers

Preparation of α-methylene ketones by direct methylene transfer

Four methods for the preparation of α-methylene ketones by direct methylene transfer are presented. The procedures were optimized in order to obtain high yields.

Mild Darzens Annulations for the Assembly of Trifluoromethylthiolated (SCF3) Aziridine and Cyclopropane Structures

We report mild new annulation approaches to trisubstituted trifluoromethylthiolated (SCF3) aziridines and cyclopropanes via Darzens inspired protocols. The products of these anionic annulations, rarely studied previously, possess attractive features rendering them valuable building blocks for synthesis platforms. In this study, trisubstituted acetophenone nucleophiles bearing SCF3 and bromine substituents in their α position were shown to undergo [2 + 1] annulations with vinyl ketones and tosyl-protected imines under mild reaction conditions.

Direct Umpolung Morita–Baylis–Hillman like α-Functionalization of Enones via Enolonium Species

Herein we report on the umpolung of Morita–Baylis–Hillman type intermediates and application to the α-functionalization of enone C?H bonds. This reaction gives direct access to α-chloro-enones, 1,2-diketones and α-tosyloxy-enones. The latter are important intermediates for cross-coupling reaction and, to the best of our knowledge, cannot be made in a single step from enones in any other way. The proposed mechanism is supported by spectroscopic studies. The key initial step involves conjugate attack of an amine (DABCO or pyridine), likely assisted by hypervalent iodine acting as a Lewis acid leading to formation of an electrophilic β-ammonium-enolonium species. Nucleophilic attack by acetate, tosylate, or chloride anion is followed by base induced elimination of the ammonium species to give the noted products. Hydrolysis of α-acetoxy-enones lead to formation of 1,2-diketones. The α-tosyl-enones participate in Negishi coupling reactions under standard conditions.

Alkylation of Indoles with α,β-Unsaturated Ketones using Alumina in Hexanes

We evaluated the influence of solvent on the alumina-promoted C3-alkylation of indoles with α,β-unsaturated ketones. We found that lipophilic solvents were generally superior to hydrophilic ones with hexanes offering the 3-alkyl indole products in high yields. Thus, we demonstrate an inexpensive and procedurally simple new process that pairs acidic alumina with hexanes to achieve this important Michael alkylation. The substrate scope includes twenty-four examples with reaction yields ranging from 61 to 96%. (Figure presented.).

Direct Photoredox-Catalyzed Reductive Difluoromethylation of Electron-Deficient Alkenes

Photoredox-catalyzed reductive difluoromethylation of electron-deficient alkenes was achieved in one step under tin-free, mild and neutral conditions. This protocol affords a facile method to introduce RCF2 (R=H, Ph, Me, and CH2N3) groups at sites β to electron-withdrawing groups. It was found that TTMS (tris(trimethylsilyl)silane) served nicely as both the H-atom donor and the electron donor in the catalytic cycle. Experimental and DFT computational results provided evidence that RCF2 (R=H, Ph, Me) radicals are nucleophilic in nature.

Efficient, direct α-methylenation of carbonyls mediated by diisopropylammonium trifluoroacetate

A very efficient method for the direct α-methylenation of carbonyl compounds, with yields up to 99%, utilizing paraformaldehyde, diisopropylammonium trifluoroacetate, and catalytic acid or base, is presented.

Tandem oxidation/halogenation of aryl allylic alcohols under Moffatt-Swern conditions

(Chemical Equation Presented) Aryl allylic alcohols are converted to halogenated unsaturated ketones or allylic halides using excess Moffatt-Swern reagent. Electron-poor aromatic rings favor formation of the halogenated ketone, while electron-donating substituents in the ortho or para positions favor formation of the allylic halide. The oxidation/halogenation reaction performs well with both oxalyl chloride and oxalyl bromide, providing access to the corresponding chlorides or bromides, respectively.

Baker's yeast reduction of α-methyleneketones

The bioreduction of α-methyleneketones, R1C(=O)C(=CH2)R2 (R1 = Me, Et, Pr, iso-Bu, Ph, CH2CH2Ph; R2 = Cl, Me, Et, n-Pr, iso-Pr, n-Bu, n-C6H13, Ph, CH2Ph), was mediated by baker's yeast (Saccharomyces cerevisiae) to obtain the corresponding α-methylketones. The R1 and R2 groups had a significant influence on the rate and enantioselectivity of the reductions. The rate of C=C bond reduction was higher than that of C=O bond reduction. Only α-methyleneketones having R1 = Me yielded α-methylketones in high enantioselectivity with e.e.s of 88-99%.

One-Step Preparation of α-Chloro-α,β-unsaturated Carbonyl Compounds by the Reaction of Silyl Enol Ethers with TiCl4-LiAlH4-CCl4

Reaction of silyl enol ethers in a system composed of TiCl4, LiAlH4, and CCl4, which generates dichlorocarbene, produced α-chloro-α,β-unsaturated carbonyl compounds in an one-step process.

Methods for the introduction of a Phenylselenium Dichloride Group into he α-position of Carbonyl Compounds. Syntheses of Enones.

Phenylselenium trichloride, PhSeCl3, direcly introduced, in fair yield, a PhSeCl2 group into the α-position of ketones with loss of HCl.To some extent, depending on the substrate, this reagent was also shown to act as a chlorinating agent toward ketones, yielding α-chloro ketones and α-phenylselenenyl ketones.The latter compounds were readily converted to selenium(IV) dichlorides by SO2Cl2 chlorination to significantly improve the overall yields of the selenetion process.The consecutive treatment of ketones with PhSeCl and SO2Cl2 could also be used for the introduction of a PhSeCl2 group, but this procedure was usually less efficient than the PhSeCl3-based one.Unsymmetrical ketones were selenated with poor regiocontrol.Aldehydes were primarily chlorinated by treatment with PhSeCl3, but consecutive treatment with PhSeCl3 and SO2Cl2 introduced a PhSeCl2 group into the α-position.Carboxylic acids and esters were ureactive toward PhSeCl3 and PhSeCl.PhSeCl3 underwent addition reactions with enones to introduce a PhSeCl2 group α or β to the carbonyl group, depending on the substrate.The carbonyl compounds substituted in the α-position with a PhSeCl2 group were easily converted to the corresponding α,β-unsaturated carbonyl compounds after hydrolysis/selenoxide elimination.Since the selenium(IV) intermediates involved were highly crustalline and easy to purify, the preparation of enones from symmetrical ketones via PhSeCl2 introduction/hydrolytic elimination was especially convenient to perform from the operational point of view.