Chemistry
30 flashcards
~15 min
Organic Chemistry - Reactions and Mechanisms
This deck goes beyond basic organic chemistry to focus on how and why reactions happen. It covers nucleophiles and electrophiles, curly-arrow notation, substitution mechanisms (SN1 vs SN2), addition and elimination reactions, free-radical substitution, and the...
About this deck
This deck goes beyond basic organic chemistry to focus on how and why reactions happen. It covers nucleophiles and electrophiles, curly-arrow notation, substitution mechanisms (SN1 vs SN2), addition and elimination reactions, free-radical substitution, and the stereochemical consequences of different mechanisms. Ideal for students moving from introductory organic chemistry into mechanism-based problem solving for A-Level, IB, or first-year university courses.
Ready to test yourself?
Flip through all 30 cards in interactive study mode.
All flashcards
Click any question to reveal the answer.
An electron-rich species that donates a pair of electrons to form a new covalent bond, often attracted to positively charged or electron-deficient centers.
An electron-deficient species that accepts a pair of electrons to form a new covalent bond, often attracted to negatively charged or electron-rich centers.
The movement of a pair of electrons from an electron-rich source (bond or lone pair) to an electron-deficient destination.
A single-step nucleophilic substitution where the nucleophile attacks the carbon from the opposite side of the leaving group, causing simultaneous bond breaking/forming and inversion of configuration.
A two-step nucleophilic substitution where the leaving group departs first to form a carbocation intermediate, which the nucleophile then attacks; can occur from either side, causing racemization.
Primary and methyl halides, due to less steric hindrance around the carbon, allowing easy backside attack.
Tertiary halides, because they form more stable carbocations and steric bulk hinders backside attack needed for SN2.
Tertiary > secondary > primary > methyl, due to increasing electron-donating alkyl group stabilization (inductive effect and hyperconjugation).
A reaction where an electrophile adds across a double or triple bond, commonly seen in alkenes reacting with halogens, hydrogen halides, or water.
In addition of HX to an unsymmetrical alkene, the hydrogen atom adds to the carbon with more hydrogens already attached, and the halide adds to the more substituted carbon (via the more stable carbocation).
A cyclic, positively charged intermediate formed when bromine adds to a double bond, before a nucleophile opens the ring from the opposite side.
A mechanism where a hydrogen atom on an alkane is replaced by a halogen atom via radical intermediates, typically initiated by UV light (e.g., methane + chlorine).
Initiation (radicals form), propagation (radicals react with molecules to form new radicals), and termination (two radicals combine to form a stable molecule).
The breaking of a covalent bond so that each fragment retains one electron, producing two free radicals.
The breaking of a covalent bond where both electrons go to one fragment, producing a cation and an anion.
A two-step elimination where the leaving group departs first to form a carbocation, followed by loss of a proton to form a double bond; favored by tertiary substrates and weak bases.
A single-step elimination where a base removes a proton while the leaving group departs simultaneously, forming a double bond; favored by strong bases and less hindered substrates.
Substrate structure (primary/secondary/tertiary), strength and bulk of the nucleophile/base, and reaction temperature.
A reaction where a nucleophile attacks the electrophilic carbon of a C=O bond, breaking the pi bond and forming a new sigma bond, common in aldehydes and ketones.
Because oxygen is more electronegative than carbon, pulling electron density away from the carbon and leaving it partially positive.
Addition polymerization joins monomers with double bonds without losing atoms; condensation polymerization joins monomers with the loss of a small molecule, usually water.
A short-lived, isolable species (like a carbocation or free radical) formed during a multi-step reaction mechanism, existing at an energy minimum between transition states.
The highest-energy, unstable arrangement of atoms during a single reaction step, representing the point of bond breaking/forming; it cannot be isolated.
Because the nucleophile attacks from the side directly opposite the leaving group, flipping the molecule's spatial arrangement like an umbrella turning inside out.
Because the flat, planar carbocation intermediate can be attacked by the nucleophile from either face with roughly equal probability, producing a mixture of both stereoisomers.
An atom or group that departs with a pair of electrons during a substitution or elimination reaction, becoming a stable ion or molecule.
Because weak bases are more stable holding the extra electron pair (e.g., halide ions), making them more willing to depart from the molecule.
Electrophilic addition of water across a C=C double bond, usually catalyzed by an acid, to produce an alcohol.
The preference of a chemical reaction to produce one structural isomer over another, often explained by intermediate stability (e.g., Markovnikov addition).
They explain and predict reaction outcomes, selectivity, and stereochemistry by tracking electron movement rather than memorizing individual reactions.