Exam I Flashcards
What is an X group? Give 3 examples.
X groups are pi donating. Examples include OMe, OR, and Cl-.
What is a Z group? Give 3 examples.
Z groups are pi withdrawing. Examples include ketones, nitro groups, and nitrile groups
The best dienes are locked into what conformation?
The best dienes are in a cis conformation.
During a Diels Alder reaction, the ____ product is preferred.
During a Diels Alder reaction, the endo product is preferred.
For a Diels Alder reaction, the endo product is ___, and the exo product is ____.
Endo=kinetic, exo= thermodynamic.
During H-X addition to dienes, you can do _ , _ addition, and _ , _ addition
You can do 1,2 addition, and 1,4 addition to the diene during H-X addition.
Diels Alder Reactions can be expedited when you have a __ sub dienophile, and a __ sub diene.
Z (pi withdrawing) dienophile, and an X(pi donating) diene.
Xylene:
two methyls on a benzene
Phenyl
benzene substituent
benzyl
phenyl with a CH2 as well
Rules for Aromaticity: (3)
Continuous cyclic array of p orbitals, planar, and 4n+2 electrons
Rules for Anti-Aromaticity
Same as for Aromaticity, except you have 4n electrons.
Aromatic Heterocycles: Pyridine
Benzene with a nitrogen with lone pair.
Aromatic Heterocycles: Pyrrole
5 membered ring with 2 double bonds and a nitrogen with a lone pair.
Aromatic Heterocycles: Furan
5 membered ring with 2 double bonds and an oxygen with 2 lone pairs, one of which is in a conjugated pi system.
The following are bad arenes for FC alkylation
Z sub arenes, and amino arenes.
Halides ( direction, and activation)
Halides are ortho/para directing, and deactivating.
Phenols in the presence of water…
lose an H
Explain how electron withdrawing groups deactivate rings from reacting with electrophiles.
Electron withdrawing groups create more positive partial charge around the ring, making it hard for a positive electrophile to attach.
Explain how electron donating groups activate rings when reacting with electrophiles.
Electron donating groups create more negative partial charge around the ring, making it easier for the positive electrophile to attach.
Why is it hard for aryl and vinyl halides to undergo substitution?
They have very unstable carbocations due to bad hybridization shapes.
What is aniline?
Benzene with an NH2 group
What factors can increase reactivity during SnAr?
more electron withdrawing groups , and more electronegative leaving groups.
L Type Ligand
neutral donor
