Synthesis and Reactivity of an Alumanyl-Tin Species to Form an Al,N-Heteroallene Derivative

The molecular chemistry of metal-metal bonds is crucial for understanding the bonding and reactivity of metal-containing molecules as well as solid metals and their alloys, especially with respect to their application as catalysts for organic transformations and industrial processes. Despite the high efficiency of the recently developed nucleophilic alumanyl anions in the synthesis of diverse Al-metal bonds, the bonding between main group metals in a low oxidation state and the Al atom remains largely unexplored. This paper describes the reaction of an alumanyl anion with a chlorostannylene precursor to afford a compound with an unprecedented covalent Al-Sn bond. The lability of the covalent Al-Sn bond renders it reactive toward the insertion of carbodiimide, N₂O, and phenylacetylene. Remarkably, the reaction with benzonitrile furnished an unprecedented Al,N-heteroallene species that contains a linear Al═N═C linkage.