Abstract
The proposed S
2 reactions of a hindered organophosphorus reactant with aliphatic and aromatic nucleophiles [Ye
,
, 2017,
, 5384-5387] were studied theoretically in order to explain the observed stereochemistry of the products. Our computations (using B3LYP as the functional) indicate that the reaction with the aliphatic nucleophile occurs through a backside S
2@P pathway while the reaction with the aromatic nucleophile proceeds through a novel S
2@Cl mechanism, followed by a frontside S
2@C mechanism.