Electrophilic Addition to Alkynes
Addition of Bromine and Chlorine to Alkynes
The reagent for this reaction is 1mol Br2 or Cl2
Product: Turn triple bond into a double bond and add two bromines or chlorines, one on each carbon on the double bond.
If the reagent is 2 moles of Br2 or Cl2
Product: Turn triple bond into single and add four bromines or chlorines, two on each carbon from the triple bond.
![addition of bromine or chlorine to an alkyne](https://static.wixstatic.com/media/d261a6_af5e2c28d7dd4d179ec7f7b19f0558b6~mv2.jpg/v1/fill/w_147,h_93,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_af5e2c28d7dd4d179ec7f7b19f0558b6~mv2.jpg)
Addition of Hydrogen Halides to Alkynes
The reagent for this reaction is 2HX where X is Cl, Br or I
Product: Turn triple bond into a single bond and add two halogens, both on the most substituted carbon from the triple bond.
![addition of hydrogen halides to alkynes](https://static.wixstatic.com/media/d261a6_fca7f203263e4dd9b91b6b4c9c1787ef~mv2.jpg/v1/fill/w_147,h_56,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_fca7f203263e4dd9b91b6b4c9c1787ef~mv2.jpg)
Hydration of Alkynes to Aldehydes and Ketones
Hydroboration-Oxidation of Alkynes
The reagent for this reaction is 1.BH3 or (Sia)2BH 2. H2O2, NaOH
Product: Turn triple bond into a single bond and add =O to the LEAST submitted carbon from the triple bond. If there is no least substituted carbon, then add to either carbon.
![Hydroboration-Oxidation of alkynes](https://static.wixstatic.com/media/d261a6_d8af431ece6a45d691c7312e34aa11ef~mv2.jpg/v1/fill/w_147,h_61,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_d8af431ece6a45d691c7312e34aa11ef~mv2.jpg)
Acid-catalyzed Hydration of Alkynes
The reagent for this reaction is H2O, H2SO4, HgSO4
Product: Turn triple bond into a single bond and add =O to the most substituted carbon from the triple bond.
![Acid- catalyzed hydration of alkynes](https://static.wixstatic.com/media/d261a6_8003a31888eb4767b1357a974a1de265~mv2.jpg/v1/fill/w_147,h_57,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_8003a31888eb4767b1357a974a1de265~mv2.jpg)
Reduction of alkynes
Catalytic Reduction of Alkynes
The reagent for this reaction is 2 H2 with Pd, Pt or Ni
Product: Turn triple bond into a single bond by adding four hydrogens one on each carbon from the triple bond.
![catalytic reduction of alkynes](https://static.wixstatic.com/media/d261a6_77286ce340de472f862d5cbf923466df~mv2.jpg/v1/fill/w_147,h_83,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_77286ce340de472f862d5cbf923466df~mv2.jpg)
Lindlar Catalyst
The reagent for this reaction is H2 with Lindlar's catalyst
Product: Turn triple bond into a CIS double bond.
![alkyne with lindlar catalyst](https://static.wixstatic.com/media/d261a6_3ee85d0c06684804a38387043f648c10~mv2.jpg/v1/fill/w_147,h_64,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_3ee85d0c06684804a38387043f648c10~mv2.jpg)
Alkynes with 2Na NH3(l)
The reagent for this reaction is 2 Na NH3(l)
Product: Turn triple bond into a TRANS double bond
![](https://static.wixstatic.com/media/d261a6_a846b9ee079847fc87e02a9933196d0a~mv2.jpg/v1/fill/w_147,h_67,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_a846b9ee079847fc87e02a9933196d0a~mv2.jpg)
![Alkyne Reaction Cheat Sheet for Organic Chemistry by Brown, Iverson, Anslyn, Foote](https://static.wixstatic.com/media/d261a6_8f96d0ece02b426db6f4763508c734d3~mv2.jpg/v1/fill/w_147,h_165,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/d261a6_8f96d0ece02b426db6f4763508c734d3~mv2.jpg)
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