Abstract
The addition of the Grignard 3,4,5-Ar(F)MgBr to aluminum(III) chloride in ether generates the novel triarylalane Al(3,4,5-Ar(F))(3)·OEt(2). Attempts to synthesize this alane via transmetalation from the parent borane with trimethylaluminum gave a dimeric structure with bridging methyl groups, a product of partial transmetalation. On the other hand, the novel alane Al(2,3,4-Ar(F))(3) was synthesized from the parent borane and trimethylaluminum. Interestingly, the solid-state structure of Al(2,3,4-Ar(F))(3) shows an extended chain structure resulting from neighboring Al···F contacts. Al(3,4,5-Ar(F))(3)·OEt(2) was then found to be an effective catalyst for the hydroboration of carbonyls, imines, and alkynes with pinacolborane.