Catalytic Synthesis of Alkynes and Diynes

The catalytic synthesis of alkynes and diynes encompasses a diverse suite of organometallic and photochemical strategies to forge carbon–carbon triple bonds with precision. Alkynes serve as versatile building blocks in pharmaceuticals, agrochemicals and advanced materials, while diynes underpin conjugated polymers and electronic devices. Progress over the past decade has focused on developing catalysts based on both precious and Earth-abundant metals, achieving enhanced regio- and stereocontrol, improved atom efficiency and expanded substrate scope. Mechanistic elucidations—ranging from radical pathways to metal–ligand cooperative processes—have guided the rational design of more sustainable and selective transformations, positioning alkyne coupling as a cornerstone of modern C–C bond-forming methodology.

Research from Nature Portfolio

Recent studies have elucidated dual reaction pathways in copper-mediated Glaser coupling under anaerobic and aerobic conditions. Under oxygen-free, photo-induced environments, copper(I) acetylides engage in a radical mechanism to generate alkynyl radicals that combine into diynes or undergo hydrogen-atom transfer to functionalise diverse substrates. In the presence of O₂, copper(I) acetylides are oxidised to mixed Cu(I/II) intermediates that proceed via oxidative coupling. This mechanistic resolution completes the radical picture, offers a mild route to energetic alkynyl species and expands the utility of copper catalysis in organic synthesis.

Catalytic Synthesis of Alkynes and Diynes publication trend

The graph below shows the total number of articles in catalytic synthesis of alkynes and diynes across all publications each year (not limited to Nature Index journals).

Technical terms

Alkyne: An organic molecule containing at least one carbon–carbon triple bond.

Diyne: A molecule featuring two carbon–carbon triple bonds.

Glaser coupling: Copper-catalysed oxidative homocoupling of terminal alkynes to form diynes.

Oxidative coupling: A reaction wherein two substrates join with concurrent oxidation facilitated by a metal catalyst.

Metal–ligand cooperative catalysis: A mechanism in which both the metal centre and its coordinated ligand actively participate in substrate activation.

Radical mechanism: A reaction pathway involving open-shell intermediates with unpaired electrons.

References

1. Anaerobic photoinduced Cu(0/I)-mediated Glaser coupling in a radical pathway. Nature Communications (2023).
2. Selective Manganese-Catalyzed Dimerization and Cross-Coupling of Terminal Alkynes. ACS Catalysis (2021).
3. Metal–Ligand Cooperative Proton Transfer as an Efficient Trigger for Rhodium-NHC-Pyridonato Catalyzed gem-Specific Alkyne Dimerization. ACS Catalysis (2021).