Haloalkanes and Haloarenes Formula Sheet

Haloalkanes are alkanes containing halogen atoms (F, Cl, Br, I), classified as primary, secondary, or tertiary depending on the carbon bonded to the halogen. They undergo three main reactions: addition (halogen/HX across double bonds), substitution (halogen replaced by nucleophile), and elimination (loss of HX to form alkenes). Substitution occurs via SN2 (single-step, backside attack, inversion, favored by primary halides/aprotic solvents) or SN1 (two-step, carbocation intermediate, racemization, favored by tertiary halides/protic solvents). Elimination includes E2 (one-step, strong base), E1 (two-step, carbocation, rearrangement possible), and E1cB (via carbanion with poor leaving groups).

Key rules: Saytzeff’s Rule favors more substituted alkenes (thermodynamic control), while Hofmann’s Rule favors less substituted alkenes (kinetic control). Solvent effects alter nucleophilicity vs. basicity. Special reactions include Wurtz, Wurtz–Fittig, Corey–House, Williamson’s ether synthesis, and Grignard reagent chemistry. Haloarenes undergo electrophilic substitution, Sandmeyer, Schiemann, and nucleophilic aromatic substitution via benzyne mechanism.