A Practical Synthesis of α-Aryl Methyl Ketones via a Transition-Metal-Free Meerwein Arylation

Abstract

We report herein a simple, scalable, transition-metal-free approach to the synthesis of alpha-aryl methyl ketones from diazonium tetrafluoroborate salts under mild conditions. This methodology uses easily accessible and nontoxic starting material and was applied to the multi-kilogram-scale preparation of 1-(3-bromo-4-methylphenyl)propan-2-one.

Intermolecular Olefin Functionalisation Involving Aryl Radicals Generated from Arenediazonium Salts

“…An industrial application of an aryl radical addition to 2-propenyl acetate leading to 3-aryl-2-propanones has recently been reported. [58] Oxygen Carbohydroxylation reactions [59] aimed at b-aryl alkohols require oxygen-centred radical scavengers that do not readily react with aryl radicals. Depending on the rate of the undesired aryl radical trapping, only activated or both activated and non-activated olefins would be applicable in the functionalisation reaction.…”

About possibility of the triplet mechanism of the Meerwein reaction

“…In recent time a number of papers describing non-catalytic examples for the Meerwein reaction appeared [1,8,9,17,18,33]. We have calculated few UC, which do react in the absence of the catalyst ( Table 2).…”

“…Due to the growing interest to the synthesis of new drugs [1][2][3], antimicrobial agents [4][5][6][7][8][9], functionalized heterocyclic compounds [10][11][12][13][14] and aromatic a-amino acids [15] on the ground of the Meerwein reaction [16], the necessity to evaluate criteria of activities of corresponding unsaturated compounds (UC) as substrates in such syntheses grows. It is a well known fact that olefins, dienes and other UC with strong electron withdrawing groups (COOH, CN, CHO, COCH 3 , etc.)…”

Retraction of “Ascorbic Acid-Promoted C–H Arylation of Heterocyclic N-Oxides through in Situ Diazotisation of Anilines: A Green and Selective Coupling Process”

“…Along with problems arising due to the high reactivity of the aryl radical intermediates, an additional challenge is the handling of the potentially unstable aryl diazonium precursors. Although these high energy species are routinely handled on large scale, [29][30][31][32] safety concerns 33 still inhibit their adoption among the wider synthetic community.…”