Relationship between the electrophilicity of substituting agents and substrate selectivity in Friedel–Crafts reactions

Is There a Minimum Electrophilicity Principle in Chemical Reactions?

“…It is shown that ω is a useful descriptor for reactivity and is frequently used in analysis of chemical reactivity of different molecules. [28][29][30][31][32][33][34][35][36][37][38][39] Variations of this quantity during molecular vibrations, 40,41 internal rotations, 42,43 and chemical reactions 40,[44][45][46][47][48][49] have been recently studied. Chamorro et al 40 found that under constants μ and ( ) r ν , there would be a minimum electrophilicity principle along a reaction path.…”

Theoretical studies of reactivity and selectivity in some organic reactions

“…Domingo et al found that electron withdrawing substitution increased the electrophilicity power of ethylene, and that the corresponding r e (x) values were consistently predicted as positive numbers. More recently, we have illustrated how the electrophilicity index quantitatively accounts for the observed substrate selectivity in Friedel-Craft benzylation and acylation [4]. In this work, we show how the electrophilicity index permits to estimate the activation/deactivation effects promoted by electron-withdrawing and electron-releasing substituents in aldehydes and ketones involved in the Baeyer-Villiger oxidation reactions [6].…”

“…The properties of interest are usually response functions with respect to perturbations. The DFT has been successful in the development of global and local reactivity indices [1,2] that have helped significantly in the study of reactivity and selectivity for a wide number of systems [3][4][5][6]. A comprehensive review about this theme has been published [7] together with a specific review about the electrophilicity index [8].…”

A reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3′-dimethylbiphenyl and the oxidation of the acetyl derivatives

“…The Friedel-Crafts acylation is a powerful and successful way to introduce new carbon-carbon bonds in aromatic compounds and is one of the most important one-step routes for the synthesis of aromatic ketones, in research laboratories and in the chemical and pharmaceutical industries [ 1 - 5 ]. Although the reaction has been known for more than 130 years it still receives attention [ 6 - 16 ] the recent interest being focused on the use of ionic liquids as solvents [ 7 ], selectivity studies [ 6 , 9 , 11 , 13 ], the application of solid catalysts [ 16 ], and still, mechanism details [ 8 , 12 , 14 , 15 ]. Simple aromatic hydrocarbons and methyl substituted derivatives have featured as substrates in both earlier and more recent studies of the reaction including benzenes [ 6 , 7 , 17 - 19 ], biphenyls and fluorene [ 11 , 13 , 20 ], naphthalenes [ 21 - 23 ], anthracenes [ 14 , 24 , 25 ], phenanthrenes [ 12 , 26 ], pyrenes [ 27 ], and chrysenes [ 28 ] and as a part of our continuing interest in Friedel-Crafts acetylations [ 11 , 13 , 21 , 28 - 31 ], we now report details of the acetylation of 3,3′-dimethylbiphenyl (3,3′-dmbp).…”