SN1 and SN2 Reactions

water (polar protic / polar aprotic solvent)

protic solvent

CH3OH (polar protic / polar aprotic solvent)

polar protic

CH3CH2OH (polar protic / polar aprotic solvent)

polar protic

Acetone (polar protic / polar aprotic solvent)

polar aprotic solvent

DMF (polar protic / polar aprotic solvent)

polar aprotic solvent

DSMO (polar protic / polar aprotic solvent)

polar aprotic solvent

MeCN (polar protic / polar aprotic solvent)

polar aprotic solvent

anything that’s the conjugate of a strong acid is a rlly good….

leaving group

Polar protic: nucleophilicity ___ down the pt

increases

Polar aprotic: nucleophilicity ___ down the pt

decreases

Bulky groups makes a nucleophile…

poor

The greater the EN, the ___ the nucleophile

worser

Polar protic solvent (SN1 or SN2)

SN1

Polar aprotic solvent (SN1 or SN2)

SN2

3* carbon (SN1 or SN2)

SN1

methyl, 1*, 2* substrate (SN1 or SN2)

SN2

All solvolysis reactions occur in __ steps

3

Tertiary carbons are __ stable than primary and secondary carbons

more

Polar protic: nucleophilicity increases___ across the pt

right to left

Polar aprotic: nucleophilicity increases ___ across the pt

right to left

Leaving group ability increases __ (up/down) the pt

down

Leaving group ability increases __ (left to right / right to left) across the pt

left to right

SN1: the ___ step is the rate determining step

first

Wat does the graph for SN1 look like

Wat does the graph for SN2 look like

An SN1 reaction w/ a negatively charged nucleophile occurs in how many steos?

2

An SN1 reaction w/ a neutral charged nucleophile occurs in how many steos?

3

SN1 reaction first step:

leaving group comes off

SN1 reaction second step

nucleophile attacks carbocation

SN1 third step (for neutrally charged nucleophiles)

Nucleophile removes hydrogen (acid-base rxn)

SN1 (unimolecular / bimolecular)

unimolecular

SN2 (unimolecular / bimolecular)

bimolecular

For which rxn (SN1 or SN2) do you have to draw attack from front and back side?

SN1 (after step 1, carbon is planar, flat, sp2 — can react from back or front)

In SN1, the rate determing step is.. (endo/exo)

endothermic

more stable product forms… (faster/slower)

faster (ex. SN1 — product w/ tertiary carbon forms faster)

Order of determining SN1 or SN2

Substrate, Nucleophile, Solvent, Leaving group

Weak lewis base (SN1 or SN2)

SN1 (weak = not negatively charged)

Strong lewis base (SN1 or SN2)

SN2 (strong = negatively charged)

Inversion of configuration (SN1 or SN2) - like only once

SN2

When we talk about allylic vs. benzylic we are referring to.. (nucleophile / substrate)

substrate

What does allylic mean

a carbon attached to a c—c double bond

What does benzylic mean

a carbon attached to a benzene ring

Rate rxn for SN1

Rate = k[substrate]

Rate rxn for SN2

Rate = k[substrate][nucleophile]