Benzene Reactions and Mechanisms

This set of flashcards covers key vocabulary associated with benzene reactions, mechanisms, and spectroscopy.

Friedel-Crafts Alkylation

AlCl3-catalyzed reaction of benzene with alkyl halides to form alkylated products.

Electrophilic Aromatic Substitution (EAS)

A reaction mechanism where an electrophile replaces an aromatic hydrogen atom.

Sigma Complex

An intermediate stage in EAS reactions, where the aromatic system is altered.

Acylium Cation

A positively charged species formed from acyl halides during Friedel-Crafts acylation.

Radical Anion

An intermediate in reactions involving single electron transfers, particularly in reductions.

Lewis Acid

A chemical species that can accept an electron pair, exemplified by AlCl3 and FeBr3.

Benzene Nitration

Electrophilic aromatic substitution reaction where benzene reacts with HNO3 and H2SO4 to produce nitrobenzene.

Rearrangement

The process by which a carbocation alters its structure to form a more stable ion during Friedel-Crafts alkylation.

Mesitylene

A compound also known as 1,3,5-trimethylbenzene, with specific NMR characteristic signals.

Proton Transfer

A step in various chemical reactions where a proton (H+) is transferred from one species to another.

Carbocation

A positively charged organic ion resulting from the removal of a leaving group in alkylation reactions.

Sulfonation of Benzene

The process of adding a sulfonyl group (SO3H) to benzene, often using fuming H2SO4.

EAS Reactivity

The tendency of an aromatic compound to undergo electrophilic aromatic substitution, influenced by substituents.

Ortho/Para-Selectivity

A preference for electrophilic substitutions to occur at the ortho or para positions relative to a substituent on the benzene ring.

Acetophenone

An aryl ketone product derived from Friedel-Crafts acylation, notable for its mass spectrum characteristics.

Fuming H2SO4

A highly concentrated sulfuric acid mixture used as a strong Lewis acid in sulfonation reactions.

Clemmensen Reduction

A two-step chemical process to convert an acyl group into a methylene group using zinc amalgam and HCl.

Electrophile (E+)

A species that seeks electrons to react and is a key participant in electrophilic aromatic substitution reactions.

Dyes from Azo Coupling

Colored compounds derived from azo reactions involving aromatic compounds, notable for extended conjugation.

Poly-Alkylation

The occurrence of multiple alkylation reactions on a benzene ring, which can complicate product formation.

Wavenumber

A measure used in spectroscopy, often corresponding to the energy of transitions in IR spectroscopy.

13C NMR Spectrum

A type of NMR spectroscopy used to determine the carbon framework of organic compounds.