Amines, Alcohols, Ethers, Epoxides, Aromatic Compounds - VOCABULARY (Organic Chemistry II)

Vocabulary flashcards covering key terms and concepts from the lecture notes on amines, alcohols, ethers, epoxides, and aromatic compounds.

Amine

Organic derivative of ammonia (NH3) in which one or more hydrogens are replaced by alkyl/aryl groups; typically basic and nucleophilic due to the nitrogen lone pair.

Primary amine (1°)

R–NH2, one alkyl/aryl group attached to nitrogen.

Secondary amine (2°)

R2–NH, two alkyl/aryl groups attached to nitrogen.

Tertiary amine (3°)

R3–N, three alkyl/aryl groups attached to nitrogen.

Quaternary ammonium salt

R4N+ salt (e.g., R4N+Cl−) formed when a tertiary amine is further alkylated, giving a positively charged nitrogen.

Lone pair on nitrogen

Nonbonding electron pair on nitrogen that contributes to amine basicity and nucleophilicity.

Nomenclature: common vs IUPAC

Common names use alkyl groups (e.g., ethylamine); IUPAC uses amino- as a prefix or -amine as a suffix.

Ethylamine (ethanamine)

CH3CH2NH2; a simple primary amine used as an example in nomenclature.

Amine basicity

Ability to accept a proton to form RNH3+; influenced by inductive effects, resonance, and solvation.

Inductive effect

Electron-donating or -withdrawing effect transmitted through sigma bonds that affects basicity.

Resonance effect (amines)

Delocalization in aryl amines (e.g., aniline) lowers basicity relative to alkyl amines.

Aniline

Aryl amine (aminobenzene); less basic than alkyl amines due to resonance with the benzene ring.

Acid-base reaction with HCl (amines)

RNH2 + HCl → RNH3+Cl−; proton transfer forming ammonium salt.

Alkylation of amines

RNH2 + R′–X → R–NHR′; formation of substituted amines.

Acylation (amide formation)

RNH2 + RCOCl → RCONHR; formation of an amide.

Diazotization

ArNH2 + NaNO2 + HCl → Ar–N2+Cl−; used in azo dye synthesis.

Aromatic amine

Amine attached to an aryl ring (e.g., aniline); generally less basic than aliphatic amines.

Amide

R–CO–NH2; nitrogen attached to carbonyl group; a nitrogen-containing functional group.

Nitrile

R–C≡N; nitrile functional group.

Nitro compound

R–NO2; nitro group-containing compounds, typically electron-withdrawing.

Azo compound

R–N=N–R′; azo linkage often colored and used in dyes.

Benzene

C6H6; simplest aromatic ring with delocalized π electrons.

Hückel’s Rule

Acyclic rule: aromatic if cyclic, planar, fully conjugated, and contains 4n+2 π electrons.

4n+2 π electrons

Number of π electrons that yields aromatic stability (e.g., benzene has 6).

π electrons

Electrons in p orbitals that participate in conjugation and aromatic stabilization.

Monosubstituted benzene

Benzene with one substituent; named as substituent + benzene.

Ortho/Meta/Para (positions)

Relative positions of substituents on a benzene ring: ortho (1,2), meta (1,3), para (1,4).

Chlorobenzene

Chlorine-substituted benzene; example used in nomenclature.

Electrophilic Aromatic Substitution (EAS)

Aromatic ring reacts with an electrophile while retaining aromaticity; steps: electrophile formation, attack by π electrons, deprotonation to restore aromaticity.

Electrophile

Electron-poor species that accepts electrons in reactions such as EAS.

Friedel–Crafts alkylation

EAS where an alkyl group is introduced onto an aromatic ring (with Lewis acid catalyst).

Friedel–Crafts acylation

EAS where an acyl group is introduced onto an aromatic ring.

Activating group

Substituent that donates electrons and increases ring reactivity (e.g., –OH, –NH2).

Deactivating group

Substituent that withdraws electrons and decreases ring reactivity (e.g., –NO2, –CF3).

Ortho/Para directors

Activating groups generally direct EAS to ortho and para positions.

Meta directors

Deactivating groups typically direct EAS to the meta position.

Benzene resonance energy

Stabilization energy from resonance; approximately 36 kcal/mol for benzene.

Nitration

EAS reaction introducing a nitro group (–NO2) onto an aromatic ring.

Halogenation

EAS reaction introducing a halogen onto an aromatic ring.

Sulfonation

EAS reaction introducing a sulfonic acid group (–SO3H) onto an aromatic ring.

Naphthalene

Two fused benzene rings; a simple polycyclic aromatic hydrocarbon.

Phenol

Hydroxybenzene; benzene ring with –OH; more activated than benzene.

Toluene

Methylbenzene; example in aromatic substitution orientation.

Oxirane

IUPAC name for ethylene oxide; a three-membered cyclic ether.

Epoxide

Three-membered cyclic ether; undergoes ring-opening under acidic or basic conditions.

Alcohol

Organic compound containing a hydroxyl (–OH) group.

Ether

R–O–R′; compound with oxygen connected to two carbon atoms.

Epoxide ring-opening (basic)

Under basic conditions, nucleophile opens less hindered carbon of the epoxide.

Epoxide ring-opening (acidic)

Under acidic conditions, ring opening occurs at the more substituted carbon.

Hydration of alkenes

Addition of water to alkenes to form alcohols.

Reduction of carbonyls

Conversion of carbonyl groups to alcohols using NaBH4 or LiAlH4.

Grignard reaction

RMgX reacts with carbonyl compounds to form alcohols after workup.

PCC oxidation

Pyridinium chlorochromate oxidizes primary alcohols to aldehydes (secondary to ketones) under mild conditions.

Esterification

Reaction of an alcohol with a carboxylic acid to form an ester and water.

Dehydration of alcohols

Loss of water to form alkenes under acid catalysis.

Aldehyde vs carboxylic acid oxidation (primary alcohols)

Primary alcohols oxidize first to aldehydes, then to carboxylic acids.

Trans diol

Diol product with hydroxyl groups added across an opened epoxide in anti orientation.

Diol

Compound containing two hydroxyl (–OH) groups.