42095-28-3

Upstream product

• 98-86-2 acetophenone 
• 78-93-3 butanone 
• 93-58-3 benzoic acid methyl ester 
• 2206-94-2 1-acetoxy-1-phenylethene 
• 78-92-2 iso-butanol 
• 343788-28-3 2-(trans-2-Phenylcyclopropyl)propane 
• 13735-81-4 1-styrenyloxytrimethylsilane 
• 145051-24-7 3-Methyl-1-phenyl-3-trimethylsilanyloxy-pentan-1-one 

Downstream Products

• 89374-88-9 (Z)-3-Methyl-1-phenyl-pent-2-en-1-one 

Relevant academic research and scientific papers

Metal-Free tert -Butyl Hydrogenperoxide (TBHP) Mediated Radical Alkylation of Enol Acetates with Alcohols: A New Route to β-Hydroxy Ketones

A metal-free TBHP-mediated radical alkylation of enol acetates with alcohols is described. This method provides a new route to a variety of β-hydroxy-ketones in moderate to good yields.

Study of the Features of the Reaction of Arylcyclopropanes with Nitrozonium Ethyl Sulfate or Nitrozonium Tetrafluoroborate

Abstract: The reactions of diaryl-, aryl-, and alkyl–arylcyclopropanes with ethyl nitrite in the presence of sulfur trioxide and sulfur trioxide dioxane complex, as well as the reactions of 1-alkyl-2-arylcyclopropanes with NOBF4 were studied. It was found that the attack of the nitrosonium cation, accompanied by the formation of a benzyl carbocation, leads to the formation of isoxazolines. The introduction of bulky alkyl substituents into the cyclopropane ring changes the regioselectivity of nitrosation, favoring the attack of the electrophilic particle on the benzyl position and leading to the competitive formation of an alkyl carbocation. Depending on the structure of the alkyl substituent, both products of intramolecular heterocyclization accompanied by skeletal rearrangements and products formed with the participation of an external nucleophile are formed.

Mechanism of Mukaiyama-Michael reaction of ketene silyl acetal: Electron transfer or nucleophilic addition?

Mechanism of Mukaiyama-Michael reaction of ketene silyl acetal has been discussed. The competition reaction employing various types of ketene silyl acetals reveals that those bearing more substituents at the β-position react preferentially over less substituted ones. However, when ketene silyl acetals involve bulky siloxy and/or alkoxy group(s), less substituted compounds react preferentially. The Lewis acids play an important role in these reactions. Enhanced preference for the more sterically demanding Michael adducts is obtained with Bu2Sn(OTf)2, SnCl4, and Et3-SiClO4 in the former reaction while TiCl4 gives the highest selectivity for the less sterically demanding products in the latter case. These results are interpreted in terms of alternative reaction mechanisms. The reaction of less bulky ketene silyl acetals are initiated by electron transfer from these compounds to a Lewis acid. On the other hand, bulkier ketene silyl acetals undergo a ubiquitous nucleophilic reaction. Such a mechanistic change is discussed based on a variety of experimental results as well as the semiempirical PM3 MO calculations.

Homogeneous catalysis. Transition metal based lewis acid catalysts

Transition metal based Lewis acids provide catalysts for the Diels-Alder and Mukaiyama reactions. These catalysts must possess an electron deficient axophilic metal center and a labile coordination position. Unlike traditional Lewis acids, those derived from transition metals can function in the presence of water and have well defined structures. It is shown how a normally electron rich ruthenium atom can be converted to a Lewis acid by incorporation of electron withdrawing ligands and ligands with hard donor atoms. This ruthenium complex, [Ru(salen)(NO)(H2O)]+, is an efficient catalyst for the Diels-Alder reaction, but in the Mukaiyama reaction, it tends to be reduced and thereby deactivated by the silyl enol ether. It is shown that the complex [TiCp*2(H2O)2]2+ (Cp* is pentamethylcyclopentadienyl) is an efficient catalyst for the Diels-Alder reaction even when water is present. Similarly, the triflato complexes [TiCp2(CF3 SO3)2] and [ZrCp2(CF3SO3)2] (Cp is cyclopentadienyl) are efficient catalysts for both the Diels-Alder and Mukaiyama reactions. All of these catalysts are effective at very low loadings of ≈ 1 mol%. Catalysis has been shown to occur via substrate-catalyst adducts and moreover these adducts are formed rapidly and reversibly as required for efficient catalysis.

ENOLBORONATES: NEW PRACTICAL REAGENTS FOR REGIOSELECTIVE ALDOL CONDENSATIONS.

Enolboronates, new enolates directly accessible from carbonyl compounds and giving aldol products regioselectively and in good yield with aliphatic and aromatic aldehydes, are described.