Precise Transfer of an Aluminium Atom: An Avenue to Aluminium Heterocycles

Synthetic chemistry targets building up molecular complexity using simple substrates through simple processes. We disclose an unprecedented Al-atom transfer strategy for the synthesis of aluminium heterocycles with high atom economy. This strategy involves an effective cycloaddition of a free carbazolyl-aluminylene with unsaturated hydrocarbons, followed by facile cleavage of the N-Al bond. The aluminylene formally behaves as an [Al+] cation transfer reagent in a two-step manner, and the only byproduct is a carbazolide salt that can be utilized to regenerate the aluminylene. The carbazolyl Al-heterocycles show unique luminescent properties, one of which exhibits dual emission. Our approach not only has a significant impact on the future design of single-atom addition reactions, but also paves the way for emissive materials based on Al-heterocycles.