Organic Chemistry: Oxidation, Reduction, and Synthetic Mechanisms

A comprehensive set of vocabulary flashcards covering organic chemistry concepts including redox reactions, substitution mechanisms, enolate chemistry, and peptide synthesis.

PCC (Pyridinium chlorochromate)

An oxidizing agent used specifically to oxidize primary alcohols to aldehydes and secondary alcohols to ketones.

$LiAlH_4$ (LAH)

A strong reducing agent that reacts with all types of carbonyls, including carboxylic acids, esters, acyl chlorides, aldehydes, and ketones.

$NaBH_4$

A mild reducing agent that can be used in the presence of $H_2O$ or $MeOH$ and is typically used to reduce aldehydes and ketones to alcohols.

Reductive Amination

A process for forming amines from aldehydes or ketones by first forming an imine or enamine intermediate, followed by reduction with $NaBH_4$.

Dean-Stark Trap

An apparatus used to remove $H_2O$ from a reaction mixture to push the equilibrium forward in reactions like imine or enamine formation.

Wolff-Kishner Reduction

A reaction that transforms aldehydes or ketones into alkanes using $H_2N-NH_2$ (hydrazine) and $KOH/H_2O$ at high temperatures ($100^{\circ}C$ to $200^{\circ}C$).

Wittig Reaction

A reaction that transforms aldehydes and ketones into alkenes using a phosphorus ylide (Wittig reagent).

Lewis Acid Catalyst

Substances like $AlBr_3$ or $FeCl_3$ used in Electrophilic Aromatic Substitution (EAS) to activate halogens or acyl/alkyl groups by lowering the activation energy ($E_a$).

Nitronium Ion

The electrophile ($NO_2^+$) formed from $H_2SO_4$ and $HNO_3$ during the nitration of a benzene ring.

Activators

Substituents that donate electron density to the benzene ring, making it more nucleophilic and acting as ortho/para directors.

Deactivators

Substituents that withdraw electron density from the benzene ring, making it less nucleophilic and acting as meta directors (with the exception of halogens).

Meisenheimer Complex

A resonance-stabilized anionic intermediate formed during Nucleophilic Aromatic Substitution ($S_NAr$) when a nucleophile attacks a benzene ring containing an electron-withdrawing group (EWG).

Benzyne

A highly reactive intermediate with a formal triple bond in a ring, formed during the elimination-addition mechanism (The Dow Process) of aromatic substitution.

Fischer Esterification

An acid-catalyzed reaction between a carboxylic acid and an alcohol to form an ester, often driven by excess alcohol or the removal of water.

Gabriel Synthesis

A multi-step method used to synthesize pure primary ($1^{\circ}$) amines from phthalimide and alkyl halides while avoiding polyalkylation.

Sandmeyer Reaction

The replacement of a diazonium salt group on a benzene ring with nucleophiles like $Cl$, $Br$, or $CN$ using copper salts.

Aldol Addition Product

A $\beta$-hydroxy ketone or $\beta$-hydroxy aldehyde formed by the reaction of an enolate with another carbonyl compound.

Claisen Condensation

The reaction of an ester enolate with another ester to produce a $\beta$-keto ester, requiring an alkoxide base that matches the ester's alkoxy group.

Hell-Volhard-Zelinsky (HVZ) Reaction

A reaction used to synthesize $\alpha$-bromo carboxylic acids using $Br_2$ and $PBr_3$.

Michael Reaction

A 1,4-conjugate addition where a nucleophile (Michael donor) attacks the $\beta$-carbon of an $\alpha,\beta$-unsaturated carbonyl compound (Michael acceptor).

Robinson Annulation

A two-part reaction combining a Michael addition and an intramolecular Aldol condensation to create polycyclic compounds.

Diels-Alder Reaction

A [4+2] cycloaddition reaction between a conjugated diene (in the s-cis conformation) and a dienophile to form a substituted cyclohexene.

TBAF (Tetrabutylammonium fluoride)

A reagent used to remove TMS (trimethylsilyl) protecting groups from alcohols.

Homolysis

The symmetrical cleavage of a chemical bond, such as $Br-Br$, where each atom retains one electron to form two radicals.

DCC ($N,N'$-dicyclohexylcarbodiimide)

A coupling reagent used in peptide synthesis to facilitate the formation of an amide bond between amino acids.