ochem sn2 backshot attack

Sn1 rate depends on…

Carbocation stability when the leaving group leaves

Sn1 rate equation

Rate = k[thing with leaving group]

Sn1 preferred degree/hinderance

3º

3º Alkyl halides probably mean…

Sn1 reaction

Sn1 nucleophile strength

weak nucleophiles, but not that important

Sn1 preferred solvent

polar protic to steal the leaving group and stabilize the charge of the carbocation and and the LG.

they also surround the nucleophile, making it weaker

The solvent has an H bonded with O,N,S like H2O

Sn1 to help stabilize the carbocation and the LG, and make the nucleophile weaker

Sn1 steps

1. leaving group leaves, carbocation formed

(hydride / methyl shift)

2. weak nucleophile attacks frontside or backside’

result: 50:50 racemic mixture of enantiomers

Sn1 sterochemistry

Raceism

raceist mixture was formed

Sn1 sterochemistry

Sn2 rate depends on

how much steric hinderance there is and nucleophile strength

Sn2 rate equation

Rate = k[thing with the leaving group][nucleophile-].

Sn2 preferred degrees/hinderance

1º less protection from getting backside attacked

1º alkyl halide is probably

Sn2

Sn2 preferred nucleophile strength

strong nucleophile so it can give backside attacks

strong nucleophile present like Cl-

probably Sn2 unless there is a polar protic solvent, which weakens the nucleophilicity of the Cl

Sn2 preferred solvent

polar aprotic to dissolve the reactants but not solvate the nucleophile, enhancing its reactivity.

Polar aprotic solvent like DMF, DMSO, acetone, acetonitrile, oxygen in a pentagon, etc

probably Sn2 so the nucleophile is still free to give backside attacks

Sn2 preferred nucleophile size

small nucleophile so it can slip in and give backside attacks

Sn2 steps

1. Strong Nucleophile attacks the substrate from the opposite side of the leaving group

   (Transition state forms, resulting in inversion of configuration.

2. Leaving group kicked out

Sn2 stereochemistry

inversion R→S, S→R

there is inversion or stereochemistry and only 1 entantiomer

Sn2 reaction because backshots