#separator:tab #html:false #tags column:4 SN1 reaction Two-step substitution through a carbocation; favors tertiary substrates and polar protic solvents tp-orgchem-reactions SN2 reaction One-step substitution with backside attack and inversion; favors methyl and primary substrates tp-orgchem-reactions E1 reaction Two-step elimination through a carbocation tp-orgchem-reactions E2 reaction One-step elimination needing a strong base and anti-periplanar geometry tp-orgchem-reactions Zaitsev's rule Elimination gives the more substituted alkene as the major product tp-orgchem-reactions Hofmann product The less substituted alkene, favored by bulky bases tp-orgchem-reactions Carbocation stability Tertiary > secondary > primary > methyl tp-orgchem-reactions Leaving group A group that departs with a pair of electrons; good ones are weak bases tp-orgchem-reactions Nucleophile An electron-rich species that attacks an electrophile tp-orgchem-reactions Electrophile An electron-poor species that accepts electrons tp-orgchem-reactions Polar protic solvent Solvent with O-H or N-H bonds, like water or ethanol tp-orgchem-reactions Polar aprotic solvent Polar solvent without O-H, like acetone or DMSO tp-orgchem-reactions Electrophilic addition Alkene pi bond attacks an electrophile, adding across the double bond tp-orgchem-reactions Hydrohalogenation Adding HX across an alkene tp-orgchem-reactions Hydration of alkenes Adding water to form an alcohol tp-orgchem-reactions Hydrogenation Adding H2 across a double or triple bond using a metal catalyst tp-orgchem-reactions Halogenation of alkenes Adding X2 across a double bond to give anti addition tp-orgchem-reactions Hydroboration-oxidation Anti-Markovnikov syn addition of water to an alkene tp-orgchem-reactions Oxymercuration-demercuration Markovnikov hydration of alkenes without rearrangements tp-orgchem-reactions Epoxidation Converting an alkene to an epoxide with a peroxyacid tp-orgchem-reactions Ozonolysis Cleaving a double bond with ozone to give carbonyls tp-orgchem-reactions Dihydroxylation Adding two OH groups across a double bond tp-orgchem-reactions Free radical halogenation Substituting H on an alkane by a halogen through radical steps tp-orgchem-reactions Radical chain mechanism Initiation, propagation, termination tp-orgchem-reactions Electrophilic aromatic substitution Replacing a hydrogen on an aromatic ring with an electrophile tp-orgchem-reactions Nitration Adding NO2 to an aromatic ring using nitric and sulfuric acid tp-orgchem-reactions Friedel-Crafts alkylation Adding an alkyl group to an aromatic ring using AlCl3 tp-orgchem-reactions Friedel-Crafts acylation Adding an acyl group to an aromatic ring tp-orgchem-reactions Ortho/para director Group that directs incoming electrophiles to positions 2 and 4 tp-orgchem-reactions Meta director Group that directs incoming electrophiles to position 3 tp-orgchem-reactions Activating group Electron-donating group that speeds up aromatic substitution tp-orgchem-reactions Deactivating group Electron-withdrawing group that slows aromatic substitution tp-orgchem-reactions Nucleophilic acyl substitution Nucleophile replaces a leaving group on a carbonyl carbon tp-orgchem-reactions Fischer esterification Acid-catalyzed reaction of a carboxylic acid and alcohol to form an ester tp-orgchem-reactions Saponification Base hydrolysis of an ester to a carboxylate and alcohol tp-orgchem-reactions Amide formation Reaction of an acid derivative with an amine tp-orgchem-reactions Grignard reaction Organomagnesium reagent adds to carbonyl compounds to form alcohols tp-orgchem-reactions Organolithium reagent Strongly basic carbon nucleophile like Grignards tp-orgchem-reactions Reduction with NaBH4 Mild reduction of aldehydes and ketones to alcohols tp-orgchem-reactions Reduction with LiAlH4 Strong reduction of carbonyls, esters and acids to alcohols tp-orgchem-reactions PCC oxidation Oxidizes primary alcohols to aldehydes tp-orgchem-reactions Jones oxidation Strong oxidation of primary alcohols to carboxylic acids tp-orgchem-reactions Swern oxidation Mild oxidation of alcohols using DMSO tp-orgchem-reactions Aldol reaction An enolate adds to a carbonyl to form a beta-hydroxy carbonyl tp-orgchem-reactions Aldol condensation Aldol addition followed by loss of water tp-orgchem-reactions Claisen condensation Ester enolate attacks another ester to give a beta-keto ester tp-orgchem-reactions Michael addition Nucleophile adds to the beta carbon of an alpha-beta unsaturated carbonyl tp-orgchem-reactions Wittig reaction Converts aldehydes and ketones into alkenes tp-orgchem-reactions Diels-Alder reaction A diene and a dienophile form a six-membered ring tp-orgchem-reactions Cycloaddition Concerted reaction forming a ring tp-orgchem-reactions Williamson ether synthesis Alkoxide attacks alkyl halide to form an ether tp-orgchem-reactions Gabriel synthesis Preparing primary amines from alkyl halides using phthalimide tp-orgchem-reactions Hofmann elimination Converts quaternary ammonium to the less substituted alkene tp-orgchem-reactions Diazonium salt Intermediate from aryl amines used to introduce many groups on rings tp-orgchem-reactions Sandmeyer reaction Replacing a diazonium group with a halide or cyanide using copper salts tp-orgchem-reactions Cannizzaro reaction Aldehydes without alpha hydrogens react to give an alcohol and an acid tp-orgchem-reactions Baeyer-Villiger oxidation Converts ketones into esters using a peracid tp-orgchem-reactions Hydrolysis Breaking a bond with water tp-orgchem-reactions Dehydration of alcohols Acid-catalyzed loss of water to form alkenes tp-orgchem-reactions Tautomerization Interconversion of keto and enol forms tp-orgchem-reactions Resonance stabilization Delocalization of electrons lowers energy tp-orgchem-reactions Hammond postulate Transition states resemble the nearest-energy species tp-orgchem-reactions Kinetic vs. thermodynamic control Fastest-formed versus most stable product tp-orgchem-reactions Inversion of configuration Stereochemical result of an SN2 reaction tp-orgchem-reactions Racemization Formation of equal amounts of both enantiomers tp-orgchem-reactions Syn addition Both groups add to the same face of a double bond tp-orgchem-reactions Anti addition Groups add to opposite faces tp-orgchem-reactions Stereospecific Different stereoisomers give different stereoisomeric products tp-orgchem-reactions Regioselective One direction of bond making is favored over another tp-orgchem-reactions Protecting group A temporary group masking a reactive site tp-orgchem-reactions Retrosynthesis Planning a synthesis by working backward from the target tp-orgchem-reactions Rearrangement (hydride shift) Carbocation moves hydrogen to become more stable tp-orgchem-reactions Polymerization Joining monomers into long chains tp-orgchem-reactions Addition polymer Polymer formed by adding monomers without losing atoms tp-orgchem-reactions Condensation polymer Polymer formed with loss of a small molecule such as water tp-orgchem-reactions Beckmann rearrangement Oxime converts to an amide under acid tp-orgchem-reactions Pinacol rearrangement Diol converts to a ketone under acid tp-orgchem-reactions Fries rearrangement Aryl ester converts to a hydroxy aryl ketone tp-orgchem-reactions Clemmensen reduction Reduces a ketone or aldehyde to an alkane using zinc and acid tp-orgchem-reactions Wolff-Kishner reduction Reduces a ketone or aldehyde to an alkane under basic conditions tp-orgchem-reactions Birch reduction Reduces aromatic rings to dienes tp-orgchem-reactions Heck reaction Palladium-catalyzed coupling of an alkene with an aryl or vinyl halide tp-orgchem-reactions Suzuki coupling Palladium-catalyzed coupling of organoboron and organohalide tp-orgchem-reactions Click chemistry Fast, reliable reactions that join molecules, like azide-alkyne cycloaddition tp-orgchem-reactions