Synthesis and properties of stable alumoles

Stable alumole and gallole derivatives have been synthesized, and their reactivity was investigated. Mes(*)-substituted alumole and gallole have tri-coordinated heavier group 13 element moieties even in the presence of Lewis bases, because of the steric hindrance of the bulky Mes(*) group. Treatment of the Mes(*)-substituted heavier group 13heteroles with Li metal afforded the Li salts of the corresponding heterole dianions. Furthermore, 1-bromo- and 1-chloro-alumole derivatives were synthesized by applying the same synthetic method as used for the synthesis of the Mes(*)-substituted alumole. In the solid state, the 1-haloalumoles exhibit dimeric structures due to the halogen-aluminum coordination interactions. Utilization of the 1-bromoalumole for the synthesis of new cyclic organoaluminum compounds through the reactions with nucleophiles and alkynes are also described.