Hi. The question is about radical attack of tBu-radical into para-position of benzophenone ketyl (2nd product in 1st attached file).
I do not understand where para-hydrogen has gone? Lithium hydride
Source: Yamataka et al. , JOC
, 54, 4706
The reference #7 is Crossland et al, Acta Chem. Scand.
, 25, 1158 , where the products are non-aromatic(see the 2nd attachtment).