Figure 4 : Reaction mechanism studies and analysis.

From: Merging rhodium-catalysed C–H activation and hydroamination in a highly selective [4+2] imine/alkyne annulation

Figure 4

(a) Regioselective alkyne hydroarylation with 2-phenylpyridine under standard catalytic conditions for [4+2] imine/alkyne annulation. (b) Results from deuterium-labelling studies. (c) Proposed pathways for regioselective deuterium transfer and equilibrium processes for H/D scrambling.