nucleophiles and bases

OH⁻

Strong nucleophile and strong base; favors SN2 and E2

OCH₃⁻ / OEt⁻

Strong nucleophile and strong base; favors SN2 and E2

CN⁻

Strong nucleophile and weak base; favors SN2

N₃⁻

Strong nucleophile and weak base; favors SN2

I⁻

Moderate nucleophile and weak base; favors SN2 and SN1

Br⁻

Strong nucleophile and weak base; favors SN2 and SN1

Cl⁻

Weaker nucleophile and weak base; can do SN2 or SN1

SH⁻ / RS⁻

Strong nucleophile and weak base; favors SN2

HS⁻

Strong nucleophile and weak base; favors SN2

SeH⁻

Strong nucleophile and weak base; favors SN2

NaH

Strong base and weak nucleophile; favors E2

tBuO⁻

Bulky strong base and poor nucleophile; favors E2

LDA

Strong bulky base and poor nucleophile; favors E2

DBU / DBN

Strong bulky base and poor nucleophile; favors E2

KOtBu

Strong bulky base and poor nucleophile; favors E2

H₂O

Weak nucleophile and weak base; favors SN1 and E1

ROH

Weak nucleophile and weak base; favors SN1 and E1

NH₃

Weak nucleophile and weak base; can do SN1 or SN2

HSO₄⁻

Very weak base; favors E1

CH₃COO⁻

Weak nucleophile and weak base; favors SN1

F⁻

Strong base and weak nucleophile; favors SN2 in polar aprotic solvents

NH₂⁻

Strong base and strong nucleophile; favors SN2 and E2

H⁻

Strong base and poor nucleophile; favors E2

CH₃⁻

Strong base and poor nucleophile; favors E2

Polar Protic Solvent

Solvent that has an- OH or -NH group and can hydrogen bond; stabilizes carbocations and anions

Polar Aprotic Solvent

Solvent that cannot hydrogen bond (no-OH or -NH); stabilizes cations but not anions

Water (H₂O)

Polar protic solvent; favors SN1 and E1

Alcohols (ROH)

Polar protic solvent; favors SN1 and E1

Ethanol (CH₃CH₂OH)

Polar protic solvent; favors SN1 and E1

Methanol (CH₃OH)

Polar protic solvent; favors SN1 and E1

Ammonia (NH₃)

Polar protic solvent; favors SN1 and E1

Acetic acid (CH₃COOH)

Polar protic solvent; favors SN1 and E1

Acetone

Polar aprotic solvent; favors SN2

DMSO (Dimethyl sulfoxide)

Polar aprotic solvent; favors SN2

DMF (Dimethylformamide)

Polar aprotic solvent; favors SN2

Acetonitrile (CH₃CN)

Polar aprotic solvent; favors SN2

THF (Tetrahydrofuran)

Polar aprotic solvent; favors SN2

SN1 Solvent Preference

Favors polar protic solvents to stabilize the carbocation intermediate

E1 Solvent Preference

Favors polar protic solvents to stabilize the carbocation intermediate

SN2 Solvent Preference

Favors polar aprotic solvents to keep nucleophile reactive

E2 Solvent Preference

Can occur in either type, but polar aprotic solvents often used with strong bases