Numerical separation of the front-side attack and double-inversion retention pathways of SN2 reactions

Uncovering an oxide ion substitution for the OH− + CH3F reaction

“…The identification of the S N 2 reaction, which does not avoid the CH 3 OH⋯F − deep well (PostHMIN1), is based on a similar method used for the numerical separation of the front-side attack and double-inversion mechanisms. 38 …”

Facilitated inversion complicates the stereodynamics of an SN2 reaction at nitrogen center

“…The configuration of the NH 2 Cl reactant (and the ‘product’ in non-reactive trajectories) and the NH 2 F product is identified as retained (retention) if the sign of the scalar product of the normal vector of the HNH plane and the NX (X = Cl, F) vector was the same as in the initial reactant configuration, otherwise it is identified as inverted (inversion). 47 …”

High-Level Systematic Ab Initio Comparison of Carbon- and Silicon-Centered SN2 Reactions

“…In addition to the well-known Walden-inversion mechanism, it was earlier recognized 2 that S N 2 reactions may occur via a high-energy front-side attack transition state (XYCH 3 ) − , where the XCY angle is around 80°. 11 , 20 , 22 , 23 , 25 , 26 , 36 − 38 Furthermore, recent studies revealed that hydrogen- (X – ···HCH 2 Y) 15 , 18 , 20 and halogen-bonded (X – ···YCH 3 ) 24 , 29 , 33 complex formations may also play key roles in carbon-centered S N 2 reactions. Moreover, reaction dynamics simulations uncovered a double-inversion pathway for the F – + CH 3 Cl S N 2 reaction, which provides products with retention of the initial configuration via double-inversion (FH···CH 2 Cl – ) and Walden-inversion (F–CH 3 –Cl) − transition states.…”

“…The X – + CH 3 Y S N 2 reactions usually proceed with Walden inversion on a double-well potential along the collinear X–C–Y arrangement via a prereaction ion-dipole complex (X – ···H 3 CY), a central transition state (X–CH 3 –Y) − , and a postreaction ion-dipole complex (XCH 3 ···Y – ). In addition to the well-known Walden-inversion mechanism, it was earlier recognized that S N 2 reactions may occur via a high-energy front-side attack transition state (XYCH 3 ) − , where the XCY angle is around 80°. ,,,,,,− Furthermore, recent studies revealed that hydrogen- (X – ···HCH 2 Y) ,, and halogen-bonded (X – ···YCH 3 ) ,, complex formations may also play key roles in carbon-centered S N 2 reactions. Moreover, reaction dynamics simulations uncovered a double-inversion pathway for the F – + CH 3 Cl S N 2 reaction, which provides products with retention of the initial configuration via double-inversion (FH···CH 2 Cl – ) and Walden-inversion (F–CH 3 –Cl) − transition states .…”