Organic Chemistry/Introduction to reactions/Review of nucleophilic substitution

Mechanism shared by SN1 and SN2 R-X (electrophile) + Nu- (nucleophile) -> Nu-R (product) + X- (leaving group) Remember, SN1 and SN2 are the same reaction just undergoing a different mechanism. SN1 quick sheet rate-determining step is unimolecular has carbocation intermediate favored by tertiary carbons that can support carbocation works better in a polar protic solvent (solvation effect) tertiary >> secondary electrophile SN2 quick sheet rate-determining step is bimolecular no carbocation intermediate nucleophile assists leaving group works better in a polar aprotic solvent methyl > primary >> secondary elecrophile steric effects important, favoring small nucleophiles