Herein, we report the Zn/Al-catalyzed C-H borylation of a range of heteroarenes using (H-BBN)2. The Ar-BBN products can be made and used in-situ, including in a conversion not possible using the pinacol boronate ester analogue. Notably, mechanistic studies indicate an unusual -bond metathesis process proceeding by the addition of both H-BBN units in dimeric (H-BBN)2 to the metal complex which is enabled by NacNac ligand non-innocence.