Aluminium redox catalysis enables cyclotrimerization of alkynes
Article Date: 2025
Article URL: https://www.nature.com/articles/s41586-025-09941-9
Article Image: (not provided)
Summary
The authors report that aluminium can be used in a redox catalytic cycle to promote the cyclotrimerization of alkynes (a [2+2+2] process) to form substituted aromatic products. This work demonstrates that a main-group element — aluminium — can undergo the necessary oxidative addition and reductive elimination steps (or equivalent redox transformations) to mediate alkyne coupling in a catalytic fashion. The paper provides experimental evidence for aluminium-containing intermediates and supports mechanistic proposals with computational analysis and literature precedent for aluminyl/reactive Al species.
Key Points
- Aluminium is employed in a redox catalytic cycle to catalyse [2+2+2] cyclotrimerization of alkynes, a reaction traditionally dominated by transition metals.
- Evidence indicates formation of aluminium–carbon intermediates (aluminacycles) that enable coupling of multiple alkyne units prior to product-forming steps.
- Main-group redox behaviour (Al(I)/Al(III) or related electronic changes) is leveraged to achieve bond-forming steps usually associated with TM oxidative addition/reductive elimination.
- Using aluminium offers potential sustainability advantages: aluminium is abundant and less toxic than many transition metals commonly used for such transformations.
- The work expands the scope of main-group catalysis and suggests routes to design other aluminium-based catalytic systems for C–C bond formation.
Context and relevance
This study sits within a growing field showing that low-valent/main-group elements can mimic transition-metal reactivity through redox cycling. It complements recent advances in aluminyl chemistry and examples of main-group oxidative addition/reductive elimination, and it emphasises that aluminium-based catalysts might deliver cost- and sustainability benefits for important C–C bond-forming reactions. For anyone following developments in sustainable catalysis or looking for alternatives to scarce/expensive transition metals, this is a notable step forward.
Why should I read this?
Short version: aluminium, the cheap and everywhere metal, just pulled off a trick normally left to pricey transition metals. If you care about greener, cheaper routes to benzene-type products or are curious how main-group elements are being pushed into proper redox catalysis, this paper is worth a skim — and a closer read if you design catalysts or synthetic routes.