Term
| the 2 effects that determine a substituent's electronic influence |
|
Definition
|
|
Term
| _____ occurs through the sigma framework, tapers off rapidly with distance, & is mostly governed by the relative electronegativity of atoms & the resulting polarization of bonds |
|
Definition
|
|
Term
| _____ takes place through pi bonds, is therefore longer range than induction, & is particularly strong in charged systems |
|
Definition
|
|
Term
|
Definition
| a substituent (such as methyl) that results in virtually no meta product when attached to a benzene ring undergoing an EAS reaction |
|
|
Term
| Why, with a methyl substituent on benzene, are the ortho & para positions favored in EAS products? |
|
Definition
| electrophilic attack at the ortho & para positions produces an intermediate carbocation in which one of the resonance forms places the positive charge next to the alkyl substituent, rendering is tertiary carbocation-like |
|
|
Term
| Why, with a methyl substituent on benzene, is the meta position not favored in EAS products? |
|
Definition
| meta attack produces an intermediate in which none of the resonance forms benefits from resonance stabilization which is seen in ortho & para attack |
|
|
Term
| Does an electron withdrawing group activate or deactivate the benzene ring? |
|
Definition
|
|
Term
| EAS reactions with electron withdrawing groups results in products at which position? |
|
Definition
| meta; they are meta directing |
|
|
Term
| What is the effect of an electron withdrawing group on carbocations resulting from electrophilic attack on a benzene ring? |
|
Definition
| the presence of an inductively electron-withdrawing substituent destabilizes the carbocations resulting from electrophilic attack at all positions in the ring |
|
|
Term
| How is the structure at which the carbocation is placed on the carbon adjacent to the EWG substituent effected by that EWG? What about next to an EDG? |
|
Definition
EWG: it is destabilized (removing electron density from a positively charged center is energetically unfavored)
EDG: the structure is stabilized |
|
|
Term
| Do EAS reactions that have an EWG on the benzene have ortho and para products? |
|
Definition
|
|
Term
| Benzene rings bearing the groups -NH2 and -OH undergo reactions which proceed very rapidly & furnish exclusively _____ products |
|
Definition
|
|
Term
| Can a substituent deactivate a benzene ring through resonance? |
|
Definition
|
|
Term
| The CO2H group is deactivating & _____ directing |
|
Definition
|
|
Term
| Do resonance withdrawing groups favor the meta position for the same reason that inductive withdrawing groups do? |
|
Definition
|
|
Term
| Resonance withdrawing groups favor the _____ position |
|
Definition
|
|
Term
| Do halogen groups activate or deactivate the benzene ring? |
|
Definition
|
|
Term
| In an EAS reaction on a benzene ring with halogen groups, which positions are favored? |
|
Definition
|
|
Term
| What is the ranking system for directing power of substituents? |
|
Definition
1. NR2, OR
2. X, R
3. meta directors |
|
|
Term
| What group is used for blocking strategies at certain positions on the benzene ring? |
|
Definition
|
|
Term
| Why is electrophilic attack on benzenamine & phenol difficult to stop at the stage of monosubstitution? |
|
Definition
| NH2 and OH groups are highly activating |
|
|
