In addition to undergoing S2-type reactions, alkyl halides and similar substrates can add to a metal center via a radical mechanism, although some details remain controversial. Reactions which are generally accepted to proceed by a radical mechanism are known however. One example was proposed by Lednor and co-workers.
;Initiation
:[[Azobisisobutyronitrile|[(CH)C(CN)N]]] → 2 (CH)(CN)C + N
:(CH)(CN)C + PhBr → (CH)(CN)CBr + Ph
;Propagation
:Ph + [Pt(PPh)] → [Pt(PPh)Ph]
:[Pt(PPh)Ph] + PhBr → [Pt(PPh)PhBr] + Ph