Alkynes

Carbon-carbon triple bonds with distinct reduction and hydration choices.

Functional group
C≡C
Also known as
alkyne, acetylenes, terminal alkynes, internal alkynes

Overview

Carbon-carbon triple bonds with distinct reduction and hydration choices.

Alkynes contain a carbon-carbon triple bond. Terminal and internal alkynes differ in substitution and reactivity. Two named examples compare cis-selective and trans-selective reduction of but-2-yne, showing why catalyst and reagent choice are part of the transformation.

Identifiers

Functional group
C≡C
Also known as
alkyne, acetylenes, terminal alkynes, internal alkynes

Properties

Terminal or internal
Terminal: R-C≡CH; internal: R-C≡C-R′.
Terminal acidity
A terminal hydrogen can be removed by a sufficiently strong base to form an acetylide; internal alkynes have no such hydrogen.

Related compounds

  • Ethyne

    Ethyne is a specific member of the alkynes family.

  • Propyne

    Propyne is a specific member of the alkynes family.

  • But-1-yne

    But-1-yne is a specific member of the alkynes family.

  • But-2-yne

    But-2-yne is a specific member of the alkynes family.

  • Phenylacetylene

    Phenylacetylene is a specific member of the alkynes family.

References

  1. Organic Chemistry: Naming AlkynesJohn McMurry · OpenStax Organic Chemistry · 2023

    Supports functional-group chemistry used to curate the linked examples. Checked 2026-09-16; named examples are applications of textbook scope, without claimed experimental yields.

  2. Organic Chemistry: Alkyne Acidity: Formation of Acetylide AnionsJohn McMurry · OpenStax Organic Chemistry · 2023

    Supports functional-group chemistry used to curate the linked examples. Checked 2026-09-16; named examples are applications of textbook scope, without claimed experimental yields.

  3. PubChem Compound Summary: Ethyne (CID 6326)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  4. PubChem Compound Summary: Propyne (CID 6335)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  5. PubChem Compound Summary: But-1-yne (CID 7846)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  6. PubChem Compound Summary: But-2-yne (CID 10419)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  7. PubChem Compound Summary: Phenylacetylene (CID 10821)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.