alkyne/alkene reagents

Alkyne: 1. xs NaNH2/NH3, 2. H2O

Reaction: Alkyne Preparation | Notes: Converts a dihalide into a terminal alkyne.

Alkyne: 1. NaNH2, 2. R'X (methyl or 1º)

Reaction: Alkylation | Notes: Adds carbon chain (R') to a terminal alkyne via SN2.

Alkyne: H2, Pt (or Pd or Ni)

Reaction: Catalytic Hydrogenation | Notes: Fully reduces an alkyne all the way to an ALKANE.

Alkyne: H2, Lindlar's Catalyst (or Ni2B)

Reaction: Poisoned Hydrogenation | Notes: Stops at the alkene. Yields a CIS (syn) alkene.

Alkyne: Na or Li metal, NH3 (liquid)

Reaction: Dissolving Metal Reduction | Notes: Stops at the alkene. Yields a TRANS (anti) alkene.

Alkyne: HX (1 equivalent)

Reaction: Hydrohalogenation | Notes: Adds H and X. Markovnikov regiochemistry.

Alkyne: HX (excess)

Reaction: Hydrohalogenation | Notes: Adds two H's and two X's. Yields a geminal dihalide (alkane).

Alkyne: HBr, ROOR (peroxides)

Reaction: Radical Hydrohalogenation | Notes: Adds H and Br. ANTI-Markovnikov regiochemistry.

Alkyne: X2 (1 equivalent)

Reaction: Halogenation | Notes: Adds two halogens. ANTI stereochemistry (yields trans-dihaloalkene). X = Cl or Br.

Alkyne: X2 (excess)

Reaction: Halogenation | Notes: Adds four halogens. Yields a tetrahalide (alkane).

Alkyne: H2SO4, H2O, HgSO4

Reaction: Acid-Catalyzed Hydration | Notes: Markovnikov addition of OH to form an enol, which tautomerizes into a METHYL KETONE.

Alkyne: 1. 9-BBN (or R2BH), 2. H2O2, NaOH

Reaction: Hydroboration-Oxidation | Notes: Anti-Markovnikov addition of OH to form an enol, which tautomerizes into an ALDEHYDE.

Alkyne: 1. O3, 2. H2O

Reaction: Ozonolysis | Notes: Cleaves triple bond. Internal alkynes become Carboxylic Acids. Terminal alkynes become Carboxylic Acid + CO2.

Alkene: HX

Reaction: Hydrohalogenation | Notes: Adds H and X. Markovnikov. Carbocation rearrangements ARE possible.

Alkene: HBr, ROOR (peroxides)

Reaction: Radical Hydrohalogenation | Notes: Adds H and Br. ANTI-Markovnikov. NO rearrangements.

Alkene: Dilute H2SO4 (or H3O+)

Reaction: Acid-Catalyzed Hydration | Notes: Adds H and OH. Markovnikov. Carbocation rearrangements ARE possible.

Alkene: 1. Hg(OAc)2, H2O, 2. NaBH4

Reaction: Oxymercuration-Demercuration | Notes: Adds H and OH. Markovnikov. ANTI addition. NO rearrangements.

Alkene: 1. Hg(OAc)2, ROH, 2. NaBH4

Reaction: Alkoxymercuration-Demercuration | Notes: Adds H and OR. Markovnikov. Yields an ether. NO rearrangements.

Alkene: 1. BH3, THF, 2. H2O2, NaOH

Reaction: Hydroboration-Oxidation | Notes: Adds H and OH. ANTI-Markovnikov. SYN addition. NO rearrangements.

Alkene: H2, Pt/Pd/Ni (or Wilkinson's Cat.)

Reaction: Catalytic Hydrogenation | Notes: Adds two H's. SYN addition. Yields an alkane.

Alkene: X2 (in inert solvent)

Reaction: Halogenation | Notes: Adds two halogens. ANTI addition. X = Cl or Br.

Alkene: X2, H2O

Reaction: Halohydrin Formation | Notes: Adds X and OH. ANTI addition. OH goes to the MORE substituted carbon.

Alkene: X2, ROH

Reaction: Haloether Formation | Notes: Adds X and OR. ANTI addition. OR goes to the MORE substituted carbon.

Alkene: 1. RCO3H (or mCPBA), 2. H3O+

Reaction: Anti Dihydroxylation | Notes: Adds two OH groups. ANTI addition (forms epoxide intermediate first).

Alkene: OsO4 / NMO (or cold, dilute KMnO4, NaOH)

Reaction: Syn Dihydroxylation | Notes: Adds two OH groups. SYN addition.

Alkene: 1. O3, 2. DMS (or Zn/H2O)

Reaction: Ozonolysis | Notes: Cleaves double bond. Yields Ketones and/or Aldehydes (does NOT over-oxidize).

Alkene: Hot, conc. KMnO4, H3O+

Reaction: Strong Oxidative Cleavage | Notes: Cleaves double bond and OVER-OXIDIZES. Yields Ketones, Carboxylic Acids (from monosubstituted carbons), or CO2 (from terminal carbons).

Sub/Elim: NaOH, KOH, LiOH

Category: Strong Nu / Strong Base | Predicts: SN2 for 1º. E2 for 2º and 3º (Zaitsev product favored).

Sub/Elim: NaOMe, NaOEt

Category: Strong Nu / Strong Base | Predicts: SN2 for 1º. E2 for 2º and 3º (Zaitsev product favored).

Sub/Elim: t-BuOK, DBU, DBN, LDA

Category: Bulky Strong Base | Predicts: E2 EXCLUSIVELY for all substrates (Hofmann product favored).

Sub/Elim: NaI, KI, NaBr, NaCl

Category: Strong Nu / Weak Base (Halides) | Predicts: SN2 for 1º and 2º. SN1 for 3º. (No elimination).

Sub/Elim: NaSH, NaSR, NaCN, NaN3

Category: Strong Nu / Weak Base | Predicts: SN2 for 1º and 2º. SN1 for 3º. (No elimination).

Sub/Elim: H2O, MeOH, EtOH

Category: Weak Nu / Weak Base | Predicts: SN1 and E1 for 2º and 3º. (E1 favored if heat is added).

Sub/Elim: Conc. H2SO4 or H3PO4 + Heat

Reaction: Acidic Dehydration | Predicts: E1 elimination of an alcohol to form an alkene (Zaitsev favored).

Sub/Elim: TsCl, pyridine (or MsCl, pyridine)

Reaction: Tosylation/Mesylation | Notes: Converts bad -OH leaving group into a great -OTs or -OMs leaving group. Retains stereochemistry.

Sub/Elim: SOCl2, pyridine

Reaction: Alkyl Chloride Formation | Notes: Converts 1º or 2º alcohol to Cl via SN2 (Inversion of stereochemistry).

Sub/Elim: PBr3

Reaction: Alkyl Bromide Formation | Notes: Converts 1º or 2º alcohol to Br via SN2 (Inversion of stereochemistry).