Exam 3 Flashcards
_____ acids give up H+ more readily.
stronger
The more _____ the conjugate base, the stronger the original acid is.
stable
The more stable the conjugate base, the _____ the original acid is.
stronger
The greater the EN of the atom/group, the _____ its acidity.
greater
The greater the EN of the atom/group, the greater its acidity. (ONLY across a _____ on periodic table).
row
Rank sp, sp2, and sp3, from least acidic to most acidic:
sp3 < sp2 < sp
Rank C, N, O, and F, from least acidic to most acidic:
C < N < O < F
The larger the size of an atom, the _____ its acidity.
greater
The larger the size of an atom, the greater its acidity. (ONLY down a _____ on periodic table).
column
Rank I-, Br-, Cl-, and F-, from least acidic to most acidic:
F- < Cl- < Br- < I-
_____ - The charge is spread out farther throughout the molecule.
delocalization
The greater the delocalization/resonance, the _____ the acidity.
greater
The greater the delocalization/resonance, the more _____ the conjugate base, and thus the _____ the acidity.
stable, greater
More resonance leads to _____ pKa, and _____ acidity.
less, more
_____ _____ -> More EN atoms on an acid -> More stable the conjugate base -> more acidity.
Inductive Effect
Inductive Effect -> More EN atoms on an acid -> More _____ the conjugate base -> _____ acidity.
stable, more
Inductive Effect: Acidity _____ as more EN groups are added near the atom.
increases
Inductive Effect: Acidity increases as more _____ groups are added near the atom.
EN
The Inductive Effect _____ the farther away the EN atoms are from the anion (conjugate base).
decreases
The Inductive Effect decreases the _____ away the EN atoms are from the anion (conjugate base).
farther
Basicity Trends are the _____ of Acidity Trends.
opposite
Bases need to have some sort of _____ _____.
lone pair
Carbon usually will NOT be a base, unless it has a _____ _____ on it.
lone pair
If a base _____ resonance upon protonation, it is a worse base.
loses
If a base loses _____ upon protonation, it is a worse base.
resonance
If a base loses resonance upon protonation, it is a _____ base.
worse
A base needs its _____ to be resonance stabilized, in order to be a strong base.
cations
Inductive effect leads to _____ basic atoms/molecules.
less
pKa = _____Ka.
pKa = -logKa
Keq = 10^pKa[_____] - pka[_____]
HB+ - HA
Keq also = 10^pKa_____ - pKa_____
right - left
HA + B -> _____ + _____
A- + HB+
The molecule that can protonate the most is also the best _____.
acid
The molecule that can deprotonate the most is also the best _____.
base
We use _____ arrows in acid/base chemistry.
mechanistic
Start arrows from where electrons _____ and point them to where electrons _____ _____.
start, end up
_____ - Donates electrons. Electron source.
nucleophile
_____ - Accepts electrons. Electron sink.
electrophile
Nucleophile - _____ electrons. Electron source.
donates
Electrophile - _____ electrons. Electron sink.
accepts
Nucleophile: Donates high energy electrons. Usually a _____ charged or _____ species with a pair of electrons in a high energy orbital.
negatively, neutral
Electrophile: _____ charged / _____ species with empty atomic orbitals or low energy antibonding orbitals.
positively, neutral
Reactions happen when you have a flow of _____ between molecules.
electrons
_____ happen when you have a flow of electrons between molecules.
Reactions
The nucleophile _____ electrons to the electrophile.
donates
The closer the _____ is to the _____, the more likely the reaction will take place.
HOMO (Highest occupied molecular orbital), LUMO (Lowest unoccupied molecular orbital)
Reaction steps: 1) Determine _____ /_____. 2) Figure out the bonds being _____ /_____. 3) Start _____ at nucleophile and end at electrophile.
nucleophile, electrophile, broken, made, arrow
In regular Alkene reactions, usually the halogen goes to the _____ substituted side UNLESS _____ is involved.
more, resonance
Carbocation stability order for substitution: _____ > _____ > _____.
tertiary > secondary > primary
_____ _____ -> C is more electron donating than H. _____ _____ -> Partial overlap of the sigma orbital of adjacent C-H or C-C bond of the alkyl group.
inductive stabilization, hyper conjugation
Inductive stabilization -> C is more _____ donating than H.
electron
Hyper conjugation -> Partial overlap of the _____ orbital of adjacent _____ or _____ bond of the alkyl group.
sigma, C-H, C-C
_____ - Preference to form a bond at one atom over the other.
regioselectivity
Due to Hammond’s Postulate, in the energy diagram, the rate determining step is endothermic. This means the TS looks more like the _____.
carbocation
Resonance stabilization is _____ important than substitution.
more
_____ _____ - When H-X is added across an unsymmetrical alkene, X prefers to bond with the most substituted C, and H bonds to the least substituted C (after resonance).
Markovnikov’s Rule
Markovnikov’s Rule - When H-X is added across an unsymmetrical alkene, _____ prefers to bond to the most substituted C, and _____ bonds to the least substituted C (after resonance).
X, H
_____ - Addition of water, H/OH across double bond.
hydration
hydration - Addition of water, _____ /_____ across double bond.
H/OH
Resonance _____ substitution.
>
In hydration reactions, the _____ usually goes to the more substituted side, while the _____ usually goes to the less substituted side (after resonance).
OH, H
In alkene reactions, the first step is that the alkene “attacks” the _____.
proton
In most reactions, the first step is that the _____ “attacks” the proton.
nucleophile
_____ _____ - H/OR added across alkene (where R is any Carbon group).
alcohol addition
Alcohol addition - _____ /_____ added across alkene (where R is any Carbon group).
H/OR
In alkene reactions, an acid helps _____ _____ to get the reaction going. Then that particular _____ serves in the rest of the reaction.
generate catalyst, catalyst
_____ _____ - The nucleophile and electrophile are in the same molecule.
intramolecular reaction
Intramolecular reaction - The nucleophile and electrophile are in the _____ molecule.
same
Intramolecular reactions happen _____ than Intermolecular reactions.
faster
Intermolecular reactions - Two _____ molecules interact.
separate
Under _____ conditions -> only neutral/positive intermediates around. Only exceptions are non-basic anions (Br-, Cl-).
acidic
Under acidic conditions -> only neutral/positive _____ around. Only exceptions are non-basic anions (Br-, Cl-).
intermediates
_____ _____ - Migration of a H, or alkyl group, to an electron deficient carbon (C+). Driving force is making a more stable C+ or to relieve strain.
carbocation rearrangement
Carbocation Rearrangement - Migration of a _____, or _____ _____, to an electron deficient carbon (C+). Driving force is making a more stable C+ or to relieve strain.
H, alkyl group
If an atom is sp2, it has a _____ _____ shape. This means that if a new group is added to it (if no chiral centers were present before), then it could be added to both the _____ or _____.
trigonal planar, top, bottom
For these particular reactions, if you are _____ chiral centers, you are always going to get a mixture of products.
creating
For these particular reactions, if you are creating chiral centers, you are always going to get a _____ of products.
mixture
If your SM had 0 chiral centers and you make a new chiral center in the product, you will have a _____ _____ of _____.
1:1 mixture of enantiomers
If your SM had a chiral center and new chiral centers are made in the product, you will have a _____ of _____.
mixture of diastereomers
_____ = No chiral centers.
achiral
Achiral = _____ chiral centers.
no
The Bromonium ion must have both Br’s on _____ or _____ (they have to be the same).
wedges, dashes
The Bromonium ion opening goes through a _____ mechanism. i.e. The I- has to get to the _____ of the _____ _____ orbital for the stereochemistry.
SN2, backside, sigma star
_____ - Chiral center changes (inverts).
inversion
_____ - Stereochemistry of the starting material affects the stereochemistry of the product.
stereospecificity
Having _____ alkene geometry will give a different diastereomer of your product in the end.
opposite
Addition of X/OH: _____ goes to least substituted C. _____ goes to most substituted C. (AFTER resonance!)
X, OH
In the addition of X/OH, _____ is in excess, allowing it to be used as a base.
H2O
Addition of ROH/X: _____ goes to least substituted C. _____ goes to most substituted C. (AFTER resonance!)
X, OR
In the addition of ROH/X, _____ is in excess, allowing it to be used as a base.
CH3OH
Keep in mind, in most addition reactions, _____ occurs to the side being added, when breaking up the bromonium/iodonium/chloronium ion.
inversion
For Hydrogenation reactions (both alkene and alkyne), you need some sort of _____ for the H2 to work off of.
metal (Pd, Pt, or Ni)
Usually a hydrogenation reaction converts an alkyne to an alkane. However, if you add a _____, then you can convert the alkyne to an alkene.
poison
_____ - Hinders the catalyst of hydrogenation reactions on alkynes, so the hydrogenation reaction will go only once instead of twice.
poison
Examples of a “poison”:
Pb(OAC)2, quinoline
Dissolving metal reduction is used to convert an alkyne to a _____ _____.
trans alkene
Dissolving metal reduction uses _____ or _____ paired with _____.
Li (pure metal), Na (pure metal), NH3 (l)
Dissolving metal reduction DOES NOT work on a _____ _____.
terminal alkyne
If you want to make a terminal alkyne an alkene, then you will need _____ _____ via a _____ reaction, instead of dissolving metal reduction.
Lindlar’s catalyst, hydrogenation
_____ - Add alkyl group to a terminal alkyne.
Alkylation
Alkylation needs a _____ _____ to deprotonate the terminal H on the alkyne, as well as a _____ alkyl halide to add.
strong base (NaNH2), primary
3 Steps to Organic Synthesis:
1) Count C’s on SM and product. Do you need to add more C’s? 2) Determine functional groups. How do they change? How can you interconvert them? 3) Work backwards (Retrosynthetic Analysis)
