Redox catalysis with environmental benign and abundant aluminium towards cyclotrimerization of alkynes

Abstract

Low-valent aluminium catalyst can promote alkyne cyclotrimerization to form substituted benzene derivatives through an Al(III)/Al(I) redox catalytic cycle. The redox activity of aluminium resembles with the transition-metal behaviour in the Reppe Reaction. This work, recently reported by Zhang and Liu, highlights the potential of aluminium, an earth-abundant main-group element to mediate complex catalytic transformations, offering a more sustainable alternative to traditional transition-metal systems. Furthermore, it provides an important outline for the design and development of redox-active aluminium complexes for future catalytic applications.

Graphical abstract

Synopsis: A carbazolyl-ligand based molecular Al(I)-complex has been developed which undergoes oxidative addition and triggers insertion, reductive elimination in presence with terminal alkynes to provide cyclotrimerization product. This news story highlights the essence of Al-catalysts in redox-catalysis due to its abundance, low toxicity, and cost-effectivity.