Scheme 12.
(a) H─D exchange between H2 and D2 enabled by (MesCCC)CoN2(PPh3) and HCl oxidative addition to (Mes- CCC)CoN2(PMe3) (reference 95), (b) oxidative addition of H2 upon styrene coordination as a key step in olefin hydrogenation catalyzed by (MesCCC)CoN2(PPh3). Ar = 2,4,6-trimethylphenyl (reference 95).