Chem 210 Final Flashcards
(218 cards)
1
Q
As pka decreases, acidity
A
increases
2
Q
A stronger acid, conj base …
A
weaker and more stable
3
Q
Formal charge=
A
VE - (#of bond lines and individual LP e)
4
Q
Octet rule
A
Atoms prefer to have 8 electrons in valence shell
5
Q
Thermodynamics
A
predicts the most energetically stable product
6
Q
Kinetics
A
determines what product will form the fastest
7
Q
The e rich reactant uses its ___ in a reaction
A
HOMO electrons
8
Q
electrons can move to ___ in response
A
sp2 and neighboring double bond
9
Q
Unsaturated bond
A
double/triple bond
10
Q
saturated
A
single bond
11
Q
Polar covalent bonds
A
C-O
C-Br
C-N
C-Cl
O-H
12
Q
Nonpolar covalent bonds
A
C-C
C-H
13
Q
HONC
A
1 2 3 4 (bonds)
14
Q
sp
A
linear
15
Q
sp2
A
trigonal planar
16
Q
sp3
A
tetrahedral
17
Q
pi electrons cannot move to a
A
sp3 atom
18
Q
prop
A
3
19
Q
but
A
4
20
Q
pent
A
5
21
Q
hex
A
6
22
Q
hept
A
7
23
Q
oct
A
8
24
Q
non
A
9
25
substituent-_____
substituent-parent-suffix
26
Alkene/alkyne always in ___
suffix
27
Resonance must maintain
conservation of charge
28
Best forms of resonance have
neutral atoms (or minimum charge), does not violate octet, never move e towards sp3 atom
29
EDG- e poor
Stabilizing
30
EDG - e-rich
Destabilizing
31
EWG e poor
Destabilizing
32
EWG e rich
Stabilizing
33
Electrophile
e poor, LUMO, full positive charge
34
Nucleophile
e rich, HOMO, full negative charge
35
To have a geometric isomer, a molecule needs
alkane
36
To have an enantiomer, a molecule needs
1 chiral center
37
To have a diastereomer, a molecule needs
2 chiral centers
38
Good LG
Weak base
39
ARIO
Atom
Resonance
Induction
Orbital
40
Explain atom in ARIO
Higher electronegativity -> better acid
41
Explain resonance in ARIO
More resonance, better acid
42
Explain orbital in ARIO
sp better than sp2 or sp3
43
Explain induction in ARIO
EWG stabilize - charge, EDG destabilize - charge
44
Constitutional isomer
same mf, diff connectivity
45
Enantiomers
Diff shape and spatial location
Mirror image (both change)
46
Diastereomer
Not mirror image (1 change)
at least 2 chiral centers
47
Alkene diastereomer
Highest priority groups on same side of alkene, (Z)
48
Higher priority group
higher atomic number
49
Acid catalysts make electrophilic atoms better
electrophiles
50
Bases make nucleophilic atoms better
nucleophiles
51
Acidic conditions form
positively charged intermediates
52
Basic conditions form
negatively charged intermediates
53
Acid/base rxns
proton transfer
54
Electrophile/nucleophile rnx
nucleophilic attack
55
Higher pka side is
favored
56
Higher LUMO, less
reactivity
57
Acids are electron
poor
58
Bases are electron
rich
59
Best LG, lowest
pkah
60
Oxidants
Cro3
61
Reductants
LiAlH4, NaBH4
62
Low energy base to high energy base
endothermic
63
SN1 will use H20, but
SN2 will not
64
Anion
negative charge
65
Cation
positive charge
66
tertiary cannot undergo
SN2
67
3 main reaction categories
Addition, substitution, elimination
68
When a molecule with a good LG interacts with a base,
elimination occurs
69
In order for elim to work, there must be a neighboring
H to protonate to form the pi bond and push out the LG
70
pka favors formation of
weaker acid
71
Good nuc, high
pkaH
72
Common acid catalysts
H2SO4
H3PO4
HCl
73
Common bases
NaOH, NaH, RMgBr
74
Nucleophiles
NaCN, NaN3, NaBH4, LiALH4
75
Bimolecular
SN2 and E2
76
Unimolecular
SN1 and E1
77
SN1 and E1 form
carbocation intermediate
78
Polar protic solvents
H20
methanol
ethanol
acetic acid
79
Polar aprotic solvents
acetone
DMSO
DMF
acetonitrile
80
Polar aprotic reaction
SN2 or E2
81
Polar protic reaction
SN1 or E1
82
SN1 reactions form
racemic mixture 50/50
83
Consider _____ of electrophile
LUMO
84
Consider ____ of nuc
HOMO
85
PCC
1 alc -> Aldehyde
2 alc -> Ketone
86
KMnO4
1 alc -> carboxylic acid
2 alc -> ketone
87
CrO3
1 alc-> carboxylic acid
2 alc -> ketone
3 alc -> NO RXN
88
H2 (lindlar)
alkyne to cis alkene
89
H2 (PD/C)
alkyne to alkane
90
LiAlH4
aldehyde -> 1 alc
ketone -> 2 alc
amide -> amine
91
NaBH4
Aldehyde -> 1 alc
Ketone -> 2 alc
92
Wedge up, dash
down
93
Wedge right, dash
left
94
Eclipsed conformation is least
stable and highest energy
95
Anti-staggered conformation is
most stable bc 180 apart
96
Most stable alkene
Most substituted (tetra)
97
cis
Z
98
trans
E
99
H and LG need to be in the same
plane for E2 to work and both must be axial
100
Axial
up or down
101
Equatorial
left or right
102
SN2 cannot do
3 carbon
103
Any 1 alkyl halide,
SN2 major
104
Only ever base
NaH and KoTbut
105
H on wedge cannot be
elim
106
Oxidants perform
oxidation
107
Oxidants are
reduced
108
Reductants perform
reduction
109
Reductants are
oxidized
110
sp hybridized atom has a total of ___ electron domains
2
111
True or false: Resonance movement can occur in a saturated molecule
false
112
True or false: A good leaving group is also a stable conjugate base
True
113
The pka of an acid is ________ the pkaH of its conjugate base
equal to
114
The ______ the conjugate base, the more stable the conjugate base
weaker
115
The ________ the pka-H, the weaker the conjugate base
lower
116
Consider the nucleophile's
HOMO
117
Consider the electrophile's
LUMO
118
A nucleophilic reactant _____ be incorporated into the structure of the product
will
119
A base (sometimes/always) deprotonates a proton from a molecule
always
120
An acid makes a molecule a more reactive
electrophile
121
A strong base has a ________ pkaH
high
122
A proton bonded to an atom that has more s character is
more acidic
123
An atom with a higher electronegativity will typically have a ________ nucleophilicity due to a _______ _________
lower, lower, HOMO
124
A low pka corresponds to a ____ acid
strong
125
Strong acids and bases have a _______ potential energy
high
126
A nucleophile uses its LP electrons to attack electrophiles. Electrophiles are attacked in their
LUMO
127
Constitutional isomers
Same molecular formula, different connectivity of atoms
128
Stereoisomers
Same connectivity but different spatial arrangement (enantiomers or diastereomers)
129
Enantiomers
Non-superimposable mirror images (Hands)
Identical physical properties
130
Diastereomers
Not mirror images
2 chiral centers
131
Chiral center
A carbon atom bonded to four different groups
132
sp2 atoms typically draw electrons
to themselves
133
sp3 atoms typically give
give away electrons
134
electron rich regions
negatively charged O, sp3 atom
135
electron poor regions
pi/weak bonds, positive charges, sp2 atoms
136
Broad peaks typically indicate
O-H (hydrogen bonding)
137
Double bonds usually give what signals
strong, sharp
138
EWG
Pull e density away from a molecule
Typically, electroneg atoms or groups with pi-accepting characterisitics
Stabilizing negative charges
Increase acidity by stabilizing the conjugate base
139
Common EWG's
NO2
CN
CF3
C=O
140
EDG
Donate e density through resonance or induction
Often groups with LP or alkyl chains
Stabilize positive charges or e-deficient systems
Decrease acidity by destabilizing the conjugate base
141
Common EDGs
OH
OR
NH2
R (alkyl groups)
142
Elimination pi bonds
increase
143
Addition pi bonds
Decrease
144
A molecule that takes up more space will be a better
acid
145
Most basic molecule will NOT have
resonance
146
Most nucleophile will have a charge
negative
147
GOOD LG, high
pkaH
148
A favored reaction will have the pkaH of the LG ________ than the pkaH of the base
lower
149
Smaller pkaH, stronger
base
150
OTS pkaH
-1
151
2^n =
of possible stereoisomers
n= # of chiral centers
152
Lower pka= acid
Stronger acid (more likely to donate protons)
153
Lower pkaH= conjugate acid
Stronger conjugate acid (more likely to donate protons)
154
Low pkaH = base
Stronger base
155
Strong acid ---> conjugate base
weak
156
Low pkaH = conjugate acid
Strong
157
Acid donates
protons
158
Base accepts
protons
159
Electrophile is charged
positive
160
Nucleophile is charged
negative
161
Electron pushing arrows etiquette
Originate from lone pair or middle of bond
Never from H
162
Antistaggered
Largest groups are 180 apart. most stable conformation
163
Gauche staggered
Largest groups are 60 apart. Less stable due to steric strain
164
Eclipsed
All groups aligned, highest energy due to torsional strain
165
A hydrogen or substituent must be anti-periplanar to a LG for
E2 reaction to occur
166
Anti-periplanar
Groups are in the same place but opposite sides of the bond axis (180)
167
For SN2 reactions, primary substrates and strong nucleophiles favor a
single-step (NaOH, NaCN)
168
For SN1 reactions, tertiary substrates stabilize the
carbocation intermediate, so weak nucleophiles work well (H20, ROH)
169
Primary carbons favor a ________ attack, but tertiary favor _____
backside, carbocation formation
170
Polar aprotic
DMSO
Acetone
DMF
171
Polar protic
H20
Alcohols
172
Polar aprotic solvents cause
SN2 and E2
173
Polar protic solvents cause
E1 and SN1
174
SN1 will cause a mixture
racemic
175
E2 eliminations favor
strong bases and crowded alkyl halides
176
E1 elims prefer
weak bases with tertiary substrates, forming a carbocation intermediate
177
KOtBu as a base typically yields (elimination)
less-substituted alkene
178
NaOH or NaOEt often yields (elimination)
more substituted alkene
179
Tosylation coverts OH into
OTS, which is a better LG than OH
180
NaBH4 is generally used for
ketones and aldehydes only
181
LiAlH4 is generally used for
carboxylic acids, esters, ketones, and aldehydes
182
PCC
stops at aldehydes for 1 alc
183
CrO3 or H2CrO4 can form
carboxylic acids from 1 alc
184
Secondary alcohols oxidize to
ketones
185
Hydrogenation of alkenes and alkynes
Alkenes/alkynes are reduced to alkanes (or alkenes)
186
H2 with Pd/Pt reduces alkenes or alkynes to
alkanes
187
H2 with Lindlar or Li/NH3 reduce alkynes to
cis alkene, trans alkene
188
O3/Zn splits alkenes to form
aldehydes/ketones
189
KMnO4 fully oxidizes alkenes to
carboxylic acids
190
OH is added to the _______ alkene in markovnikov hydration of alkenes
most-substituted carbon
191
OH is added to the _______ alkene in anti-markovnikov hydration of alkenes
less-substituted carbon (typically cis)
192
Bromination of alkenes
Each double bonded carbon gains one bromine atom
193
Downfield
ppm increases, deshielded protons (near electroneg atoms or pi-systems)
194
Upfield
ppm decreases, shielded protons (far from electroneg groups)
195
N+1 rule to find splitting group
n= number of equivalent neighboring protons
196
Singlet splitting pattern
0 neighbors
197
Doublet splitting pattern
1 neighbor
198
Triplet splitting pattern
2 neighbors
199
Quartet splitting pattern
3 neighbors
200
Nieghboring non-equivalent protons
split each other's signals
201
Protons attached to the same atom
do not split each other
202
Oxidation #
increases when oxidation
203
Oxidation # decreases when
reduction
204
Reduction is the same as
addition and hydration
205
Oxidation is the same as
elimination and dehydration
206
A tri-sub alkene is ______ stable than a mono-sub alkene
more
207
Bulky groups on chair cyclohexanes prefer to be on _______ bonds
equatorial
208
Tertiary cannot undergo
SN2
209
NaCN only functions asa
nucleophile
210
The LG and H should be _______ on chair cyclohexane
both be axial
211
Stereocenters that undergo SN2 will ______ its stereochemical configuration
invert
212
In an E2 reaction, the major product orients the bulkiest group trans (true/false)
true
213
The LG and H must be
anti for E2 to perform
214
Tertiary and 2 alkyl bromide can readily undergo
E2
215
An anion with large steric bulk cannot function as a
nucleophile
216
An oxidant ______ an organic compound
oxidizes
217
An oxidant is _____ in an organic reaction
reduced
218
CrO3 will react with
1 alc and 2 alc, NOT 3 alc
