Premium
Nucleophilic Substitution (S N 2): Dependence on Nucleophile, Leaving Group, Central Atom, Substituents, and Solvent
Author(s) -
Hamlin Trevor A.,
Swart Marcel,
Bickelhaupt F. Matthias
Publication year - 2018
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201701363
Subject(s) - chemistry , nucleophile , leaving group , electrophile , atom (system on chip) , nucleophilic substitution , substitution reaction , carbon atom , group (periodic table) , transition state , computational chemistry , stereochemistry , carbon group , solvent , medicinal chemistry , ring (chemistry) , organic chemistry , catalysis , computer science , embedded system
Abstract The reaction potential energy surface (PES), and thus the mechanism of bimolecular nucleophilic substitution (S N 2), depends profoundly on the nature of the nucleophile and leaving group, but also on the central, electrophilic atom, its substituents, as well as on the medium in which the reaction takes place. Here, we provide an overview of recent studies and demonstrate how changes in any one of the aforementioned factors affect the S N 2 mechanism. One of the most striking effects is the transition from a double‐well to a single‐well PES when the central atom is changed from a second‐period (e. g. carbon) to a higher‐period element (e.g, silicon, germanium). Variations in nucleophilicity, leaving group ability, and bulky substituents around a second‐row element central atom can then be exploited to change the single‐well PES back into a double‐well. Reversely, these variations can also be used to produce a single‐well PES for second‐period elements, for example, a stable pentavalent carbon species.