Synthesis and Reactivity of Fluorinated Triaryl Aluminum Complexes

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. 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. 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.