Chem 231-31 Quiz 3: Alkyl Halides, Reagents, and Reaction Mechanisms

Vocabulary flashcards covering reagent and solvent classifications, alkyl halide structures, mechanisms, and stereochemical/regiochemical concepts from Chem 231 Quiz 3.

Base only

A classification of reagents that act strictly as Brønsted-Lowry bases to abstract protons without functioning as nucleophiles in substitution reactions.

Strong base/strong nucleophile

A classification of reagents that possess both high basicity and strong nucleophilic character, capable of promoting both elimination and substitution pathways.

Nucleophile only

A classification of reagents that attack electrophilic carbons to form bonds without exhibiting significant basicity.

Weak base/weak nucleophile

A classification of reagents characterized by low basicity and weak nucleophilicity, commonly participating in unimolecular ($S_N1$ and $E1$) reaction pathways.

Polar protic solvent

A solvent classification for liquids that possess a dipole moment and have hydrogen atoms directly bonded to electronegative atoms (such as oxygen or nitrogen), enabling them to engage in hydrogen bonding.

Polar aprotic solvent

A solvent classification for liquids with significant dipole moments that lack acidic protons bonded to heteroatoms, preventing them from hydrogen bonding with nucleophiles (for example, N,N-dimethylformamide).

Tertiary alkyl halide

An alkyl halide classification where the alpha carbon bearing the halogen atom is covalently bonded to three other carbon atoms.

Secondary alkyl halide

An alkyl halide classification in which the alpha carbon attached to the halogen is covalently bonded to two other carbon atoms.

Primary alkyl halide

An alkyl halide classification in which the alpha carbon bearing the halogen is bonded directly to only one other carbon atom.

Ethoxide ($CH_3CH_2O^-$)

A specific reagent classified as a strong base/strong nucleophile, commonly used to drive elimination and substitution reactions.

$\beta$-carbon

Any carbon atom situated directly adjacent to the alpha carbon that bears the leaving group in an alkyl halide.

$\beta$-hydrogen

A hydrogen atom attached directly to a beta carbon that can be abstracted by a base during an elimination reaction.

Transition state

The highest energy molecular structure along a reaction coordinate, representing a transient state where bonds are in the process of breaking and forming.

Arrow pushing mechanism

A formal chemical drawing convention that uses curved arrows to illustrate the movement and reorganization of electron pairs throughout a reaction.

Regiochemistry

The preference for chemical bond formation or bond cleavage to occur predominantly at one constitutional site over other possible sites on a molecule.

Stereochemistry

The three-dimensional spatial arrangement of atoms within a molecule and the study of how this orientation directs the stereochemical outcome of a reaction.