chapter 9

sn1, sn2

Nucleophilic substitution

when a nucleophile replaces a LV leaving group

Leaving group

group that is displaced or lost (sub or elim)

^-OH

alchohol -OH

^-OR

ether -OR

^-SH

thiol

^-SR

sulfide

^-C≡CH

alkyne

^-C≡N

nitrile

I^-

alkyl iodide

^-N≡N⁺≡N^-

alkyl azide

NH3

alkylammomium ion

H2O

alcohol

CH3OH

ether

SN2 regioselectivity

N/A

SN2 stereoselectivity

Inversion of Configuration

Bimolecular

2 species involved in rate determining step

unimolecular

1 species involved in rate determining step

SN2 reaction molecular

bimolecular

SN1 reaction molecular

unimolecular

solvolysis

nucleophilic substiution in which the solvent is also the nuclephile

SN1 Regioselectivity

N/A

SN1 Stereoselectivity

N/A

SN2 governed by

sterics

SN1 governed by electronics

SN2 can occur with what degree LV alkane

1 degree, and 2 degree haloalkane

effect of beta branch on SN2 reaction rate

more branch, slower reaction

the more stable the leaving the group the _____ it is at leaving

better

nuclepphilicity

ability of a nuclephile to replace a leaving group

polarity

how well a solvent can insulate opposit charges from one another

non-polar solvent ______ at screening charges

bad

polar solvent is ______ at screening charges

good

protic solvent

solvent that is a H bond donor

examples of protic solvents

H2O, MeOH, EtOH

Aprotic Solvent

solvent that can’t be a H bond donor, there is not H bonded to a molecule with a high EN (N, O, S)

Polar Aprotic examples

DMSO (dimethylsulfoxide), CH3CN (acetonitrile), DMF(dimethylformamide)

Nonpolar aprotic

Et2O(diethyl ether), hexane