Mechanistic Insights Into the Rhodium-Catalyzed C–H Alkenylation/Directing Group Migration and [3+2] Annulation: A DFT Study

The
mechanism of the rhodium-catalyzed C–H alkenylation/directing
group migration and [3+2] annulation of N-aminocarbonylindoles
with 1,3-diynes has been investigated with DFT calculations. On the
basis of mechanistic studies, we mainly focus on the regioselectivity
of 1,3-diyne inserting into the Rh–C bond and the N-aminocarbonyl directing group migration involved in the reactions.
Our theoretical study uncovers that the directing group migration
undergoes a stepwise β-N elimination and isocyanate reinsertion
process. As studied in this work, this finding is also applicable
to other relevant reactions. Additionally, the role of Na+ versus Cs+ involved in the [3+2] cyclization reaction
is also probed.