EAS vs. NAS vs. Elimination/Addition Flow Chart

This flow chart is general and assumes the substrate is aromatic.

Back to Web Book   See entire flow chart

Are the reagents strongly electrophilic or stongly nucleophilic?
Generally Electrophilic reagents have some sort of strong acid involved (AlCl3, NHO3, etc.).
Strongly Nucleophiles involve some sort of strong base (NH2, OH)

Electrophilic
Provided the ring is activated enough, this is probably an EAS reaction 		Nucleophilic

Does the substrate have a good leaving group? (e.g. Br, Cl?)
No
None of the described reactions. 		Yes

Does the substrate have one or more electrons withdrawing group ortho and or para to the leaving group?
Yes
The reaction is probably a Nucleophilic Substitution 		No

Are the reaction conditions such that a very high temperature is being used?
Yes
The reaction is probably an elimination/additon. 		No
None of the proposed reations will occur.