Organic Chemistry Synthesis and Reaction Mechanisms

Inventory of reagents, mechanisms, and specific chemical naming conventions for aromatic substitutions, organometallics, and carbonyl chemistry based on lecture notes.

Halogenation Catalysts

Catalysts such as $\text{FeBr}_3$, $\text{FeCl}_3$, $\text{AlBr}_3$, or $\text{AlCl}_3$ used to give the electrophile catalysts for aromatic substitution.

Sulfonation Reagents

$\text{SO}_3$ and $\text{H}_2\text{SO}_4$.

Friedel-Crafts Alkylation Hydride Shift

A mechanism where a primary halogen will create a secondary carbocation via a hydride shift to make a more stable carbocation, which becomes the major product.

Friedel-Crafts Alkylation Limitation

Cannot react with nitrobenzene; however, heat is required for it to react with a nitrobenzene.

Friedel-Crafts Acylation Product

Results in a ketone product.

Organolithium Reagents Quantity

Lithium is always used in quantities of 2 ($2\text{Li}$) even if not explicitly stated.

Alkenyl Grignard Formation

$\text{sp}^2$ hybridized alkenyl Grignard reagents require heat ($60^{\circ}\text{C}$) to react.

Gilman Reagent

Formed using $\text{CuBr}$ and dry ether; it is considered mildly reactive.

Organometallic Epoxide Attack

If it is a strong nucleophile ($\text{Nu}$), it will attack the less substituted carbon ($\text{B}$).

Dichlorocarbene Preparation

Prepared using $\text{HCCl}_3$ and $\text{KOtBu}$.

Simmons-Smith Reagent (Carbenoid)

Uses $\text{Zn}(\text{Cu})$ and behaves like carbenes to create cyclopropanes.

Suzuki Coupling Catalyst

$\text{Pd}(\text{PPh}_3)_4$ is needed as a catalyst to pair $\text{sp}^2$ and $\text{sp}^3$ carbons.

Oxidation of Alcohols to Aldehydes/Ketones

Achieved using $\text{PCC}$ or $\text{PDC}$; $\text{H}_2\text{CrO}_4$ is used for further oxidation.

PAPLAD Mnemonic

Mnemonic for acetyal formation: $\text{P}$ (Proton transfer), $\text{A}$ (Attack nu), $\text{P}$ (Proton transfer), $\text{L}$ (Leaving group), $\text{A}$ (Attack nu), $\text{D}$ (Deprotonation).

Protecting Group for Ketones

$\text{Ethylene glycol}$ and $\text{TsOH}$ are used to protect ketones; they are more stable and can be removed later.

Imine Formation

Nucleophilic acyl addition with a primary nitrogen ($\text{RNH}_2$) at $\text{pH } 4$.

Oxime Formation

Reaction of a carbonyl with $\text{H}_2\text{NOH}$ at $\text{pH } 4$.

Hydrazone Formation

Reaction of a carbonyl with $\text{H}_2\text{NNH}_2$ at $\text{pH } 4$.

Wolff-Kishner Reduction

The reduction of a hydrazone to an alkane.

Enamine Formation

Nucleophilic acyl addition using a secondary amine ($\text{R}_2\text{NH}$).

LiAlH$_4$

A strong hydride reagent that is very reactive and must use a dry solvent.

NaBH$_4$

A hydride reagent that can be used at room temperature with $\text{MeOH}$ as a solvent; it reduces $\text{C}=\text{O}$ bonds only.

Pd/C with H$_2$ (1 eq)

Will reduce only the $\text{C}=\text{C}$ double bond.

Wittig Reaction

Reaction of an aldehyde or ketone with a phosphonium ylide ($\text{Ph}_3\text{P}=\text{CR}_2$) to form an alkene.

Stabilized Wittig Ylide

A conjugated ylide with resonance that produces the trans product as the major product.

Unstabilized Wittig Ylide

An ylide with no conjugation or resonance that produces the cis product as the major product.

Baeyer-Villiger Oxidation

Uses a peroxyacid ($\text{RCO}_3\text{H}$) to oxidize a ketone into an ester.