Nucleophilic substitution reaction of 1-phenylethyl chlorides in methanol

Abstract

Nucleophilic substitution reactionsof 1 -(Y-pheny1)ethyl chlorides with X-anilines have been investigated in methanol at 65.0"C. A n isokinetic point is obtained at a,?= ca. -0.23 with px = 0; the sign of px changes at this point from positive for the relatively strong electron donating Y substituents t o negative for the more electron withdrawing Y substituents.The magnitude of the cross-interaction constant, pxy, between the substituents X and Y is unusually large with the relatively small magnitude of pxo resulting in an observable isokinetic point at PXU a,+= -~ = -023.

Kinetics and Mechanism of the Pyridinolysis of Bis(2,6-dimethylphenyl) Chlorophosphate in Acetonitrile

“…18 The anilinolyses of Y-benzhydryl chlorides [YC 6 H 4 CH(C 6 H 5 )Cl] in methanol also exhibited the change of the sign of ρ X depending on Y substituents (min; ρ X = -0.76 with Y = 4-NO 2 and max; ρ X = +0.95 with Y = 4-CH 3 ). 19 The positive ρ X values of both reaction systems were interpreted in terms of a TS structure in which nearly complete bond formation between the nucleophile and cation formed in an ion-pair pre-equilibrium is coupled with a TS imbalance phenomenon, advocated by Jencks and Bernasconi.…”

Significant Substituent Effects on Pyridinolysis of Aryl Ethyl Chlorophosphates in Acetonitrile

“…3 The reactions of some substrates with X-anilines gave isokinetic phenomena, ρ j = 0 at σ i,iso , as follows: (i) 1-Y-aryl ethyl chloride with ρ XY = -2.05, giving ρ X = 0 at σ Y,iso = -0.23; 4 (ii) Y-benzhydryl chlorides with ρ XY = -1.46, giving ρ X = 0 at σ Y,iso = 0.22;…”

Kinetics and Mechanism of the Pyridinolyses of Dimethyl Phosphinic and Thiophosphinic Chlorides in Acetonitrile

“…8 The anilinolyses of Y-benzhydryl chlorides in MeOH-MeCN also exhibited the change of the sign of ρ X depending on Y substituents. 9 The positive ρX values were interpreted in terms of a TS structure in which nearly complete bond formation between the nucleophile and cation formed in an ionpair pre-equilibrium is coupled with a TS imbalance phenomenon, advocated by Jencks 10 and Bernasconi.…”