Chapter 6

alkyl halide

halogen bonded directly to an sp3 carbon

primary alkylhalide

halogen carbon bonded to 1 carbon

secondary alkylhalide

halogen carbon bonded to 2 carbons

tertiary alkylhalide

halogen carbon bonded to 3 carbons

concerted reaction

new bond forming and old bond breaking

sn2 reaction properties

rate = K[aldehyde][nu], strong Nu, polar aprotic solvent, Ch3X>1°>2°, no rearrangements or carbocation

sn1 reaction properties

rate = k[alkylhalide], 3°>2°, polar protic solvent, weak Nu, racemic, rearranges, carbocation

nucleophilic strength

faster: less bulky, stronger nucleophiles, negative nucleophiles, decreases left to right, increases up to down

strong nucleophiles

I-, -NH2, RO-, HO-, -CN, RS-

medium strength nucleophiles

RSH, RNH2, NH3

weak nucleophiles

F-, ROH, H2O

solvent effects on sn2

aprotic solvents (acetone, DMP) make reaction faster

good leaving groups properties

are electron-withdrawing, stable (not a strong base), polarizable (electron cloud can be distorted)

good leaving groups examples

Cl-, Br-, I-, sulfonates

neutral molecules are __ leaving groups

good, H2O, ROH, NR3

sn2 relative rates

CH3X>1°>2°

steric hinderance

bulk

racemization

sn1 products can be R or S

step 1 sn1

formation of carbocation

step 2 sn1

attack of the nucleophile

step 3 sn1

if the nucleophile is neutral, it needs to be deprotonated

sn1 relative rates

3°>2°>1°>CH3X

methyl halide

Vinyl halides

Halogen is bonded to an sp2 carbon of alkene

Aryl halides

Halogen is bonded to an sp2 carbon on a benzene ring.

primary alkylhalide

halogen bonded to 1 carbon

-ene

double bond, but methylene means two Hs bonded to a C

n in IUPAC name

normal, the chain is straight and unbranched

iso in IUPAC name

branched (CH3)2CH

tert IUPAC name

the carbon attached to the functional group is bonded to 3 other atoms

ring systems sn2 reaction

turns trans into cis and vice versa

fisher projections sn2 reaction

swaps sides of the affected row, not the unaffected one