Electrofugality index for benzhydryl derivatives

Theoretical substituent electrophilicities

“…In fact, good correlations have been obtained by various groups, between the global electrophilicities of a family of substituted compounds and some constant related with their reactivity. Examples include linear relationships involving global or group electrophilicities in a variety of processes, such as the reactivity of benzhydryl carbocations, 19,22 in the Baeyer-Villiger reaction of aldehydes and ketones, 23 in the hydride affinities of quinones, 24 in the reaction of aryl benzoates with cyanide, 25 or of a,b-unsaturated carbonyl compounds with glutathione. 26 These examples only add to the ones presented in the present work.…”

Predicting the quality of leaving groups in organic chemistry: Tests against experimental data

“…Analysing our results, the halogens tend to be ordered correctly, but these indicators perform poorly for the remaining families. Most previous work in this field [9,11,8,10] used chemical families that are very similar (three or more of the atoms that connect the nucleofuge to the residual are exactly the same) or halogens. In addition, the leaving groups were usually small molecules in which the molecular conformation is preserved by the dissociation process.…”

“…The indicators considered here seem very sensitive to functional groups that impact p electrons [10]. For the phosphinates locality (that is including the charge and Fukui function of the atom of the leaving group that is bonded to the substrate) improves the correlations, but for the carboxylates and sulphonates including locality worsens the results.…”

“…This indicator has also proved useful in other contexts and studies [13,10,9,15]. The idea behind this indicator was that the nucleofugality of a leaving group may be described as the energy difference between the anion and some ideal charge q ðidealÞ a .…”

“…These properties are closely related to the energy cost of accepting an electron, the charge of the leaving group, and its susceptibility to electron transfer. As a result there are several indicators in the literature that attempt to order the experimentally observed leaving ability [8][9][10][11][12][13][14]. To model nucleofugality we consider the leaving groups either in complete isolation or bonded to an sp 3 hybridised carbon of a simple molecule.…”