Strong Coordination of Tetraphenylborate Anion to Copper(I) Bipyridine and Phenanthroline-Based Complexes and Its Effect on Catalytic Activity in the Cyclopropanation of Styrene

The synthesis, characterization, and cyclopropanation activity of tetrahedral copper(I) complexes with bipyridine- and phenanthroline-based ligands containing strongly coordinated tetraphenylborate anions are reported. CuI(bpy)(BPh4), CuI(phen)(BPh4), and CuI(3,4,7,8-Me4phen)(BPh4) complexes are the first examples in which the BPh4− counterion chelates a transition metal center in bidentate fashion through η2 π interactions with two of its phenyl rings.