Textbook Notes (368,566)
Canada (161,966)
Chemistry (256)
CHMB42H3 (16)
Chapter 15

CHMB42 Chapter 15.doc

4 Pages
131 Views
Unlock Document

Department
Chemistry
Course
CHMB42H3
Professor
Wanda/ Lana
Semester
Summer

Description
Chapter 15 Reactions of Substituted BenzenesNomenclature of Disubstituted and Polysubstituted BenzenesOrtho adjacent substituents on a benzeneMeta substituents separated by one carbonPara substituents located opposite one anotherIf two substituents are different they are listed in alphabetical order where the first mentioned substituent is given the 1positionThe ring is numbered in the direction that gives the second substituent the lowest numberIf one of the substituents can be incorporated into a name that name is used and the incorporated substituent is given the 1position 2chlorotoluene or orthochlorotolueneA few disubstituted benzenes have names that incorporate both substituentsFor polysubstituted benzenes the substituents are numbered in the direction that results in the lowest possible numbers and the substituents are listed in alphabetical order 2bromo4chloro1nitrobenzeneSome Substituents Increase the Reactivity of a Benzene Ring and Some Decrease Its ReactivityActivating Substituents substituents that donate electrons into the benzene ring stabilize both the carbocation intermediate and the transition state leading to its formationDeactivating Substituents substituents that withdraw electrons from the benzene ring destabilize the carbocation intermediate and the transition state leading to its formationInductive Electron Withdrawal if a substituent that is bonded to a benzene ring is more electron withdrawing than a hydrogen it will draw the s electrons away from the benzene ring more strongly than a hydrogen will NH because it is 3more electronegative than HAlkyl substituents are more electron donating than a hydrogen because of hyperconjugationDonate Electrons by Resonance if a substituent has a lone pair on the atom directly attached to the benzene ring the lone pair can be delocalized into the ring NH OH OR and Cl and it also withdraws electrons inductively more 2electronegative than HWithdraw Electrons by Resonance if a substituent is attached to the benzene ring by an atom that is doubly or triply bonded to a more electronegative atom the p electrons of the ring can be delocalized onto the substituent CO SOH 3and NO2Electrondonating substituents increase the reactivity of the benzene ring toward electrophilic aromatic substitution activating substituentsElectronwithdrawing substituents decrease the reactivity of the benzene ring toward electrophilic aromatic substitution deactivating substituentsTABLE 151 on page 684Moderately activating substituents can donate electrons by resonance in two competing directions into the ring and away from the ringHalogens are weakly deactivating substituents because halogens both donate electrons into the ring by resonance and withdraw electrons from the ring inductively all halogens withdraw electrons inductively more strongly than they donate electrons by resonance FClBrI in donating electronsModerately deactivating substituents all have a carbonyl group directly
More Less

Related notes for CHMB42H3

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit