Oxygen Containing Reactions Flashcards
What are typical nucleophiles?
Alcohols, amines, hydrides
What are typical electrophiles?
Carbonyl carbon, phosphate groups
Only a ___ reactive molecule can form a ____ reactive molecule
More; less
Nucleophiles = Lewis ____
Bases
Alcohol attacks carbonyl C of COOH => ______
Ester
Alcohol attacks ketone/aldehyde => ______
Hemiketals/hemiacetals
Across a row, nucleophilicity _____
Increases
Good leaving group = _____ in solution
Stable
Atoms that leave as ____ = great LGs
Gases
_____ electron shells (_____ periods) => _____ charges => ______ LG and _____ nucleophile
More; higher; distribute; good LG; bad nucleophile
Weaker nucleophile can be an LG through _________ _______ reaction
Nucleophilic substitution
Best nucleophile = ______ _______
Strong base
Nitrogen = ______ nucleophilic than oxygen
More nucleophilic
Boiling point of OH goes _____ with molecular weight and ______ with branching
Up with MW; down with branching
OH has higher melting/boiling points than alkanes due to ______
Hydrogen bonding
OH typically acts as ____
Nucleophile
Alcohols = electron _____ group
Donating
Electron withdrawing groups make alcohols more ______
Acidic by drawing electron density away from acidic proton => increased partial positive charge
Electron donating groups make molecules more ____
Basic by stabilizing positive charge
Alkyl groups = electron ______ groups
Donating
Trend of alcohol acidity
Greater number of EDGs => weaker acid
Strongest to weakest alcohol acid:
Methyl > primary OH > secondary > tertiary
_____ OH has most _____ groups (which are _____)
Tertiary OH has most alkyl groups (EDGs) => makes it want to pick up proton (basic)
Hydrocarbons = electron _____
Electron donating
Alcohols = _____ LG b/c ______
Bad LG b/c reactive in solution
Alcohols become better LG by being _____ or ______
Protonated or converted to ester (sulfonate)
Formation of sulfonates = what type of reaction?
Nucleophilic substitution (OH = nucleophile)
Commonly used sulfonates = ____ and _____
Tosylates and mesylates
Sulfonates are useful for _____
Protection of alcohols (prevents OH from acting as acid or undergoing undesired reactions)
Ethers
R-O-R
- Non-reactive
- Usually shows up as solvent
Amines are ____ nucleohpile and _____ LG compared to O
Better nucleophile; worse LG
When N only appears w/ 3 bonds => ______
Draw in a lone pair
N acts as a nucleophile where lone pair attacks ______
Positive charge
Electron ______ groups on amine _____ basicity
Withdrawing; decrease
Donating; increase
Electrophiles usually have ______
Positive charge
Almost always carbonyls
Carbonyl has ______ stereochemistry
Planar => leaves space above and below to be attacked
Carbonyl C has a partial ______ charge
Positive
Carbonyl becomes more ______ by e- ______ groups
Stable; donating
Reactive; withdrawing
Most reactive carboxylic acid derivative = ______
Acyl chloride
- Cl pulls e- density
Least reactive COOH derivative = ______
Amide (O=CNH2)
- N donates e- density to C
If a carbonyl has a good LG => it will undergo ______
Nucleophilic substitution
- Cl or -OR groups leave
If a carbonyl does not have a good LG => it will undergo ______
Nucleophilic addition
- Aldehydes and ketones