Theoretical insights into the mechanism of rhodium‐catalyzed, PIII‐directed regioselective CH arylation of indole with anhydride

Abstract

AbstractDensity functional theory calculations were performed to study the reaction mechanism of Rh(I)‐catalyzed, P(III)‐directed regioselective CH arylation of indole with anhydride through decarbonylative cross‐coupling. This mechanism involves four major steps: CH activation, oxidative addition, decarbonylation, and reductive elimination. Through this theoretic study, we find that the CH bond activation was accomplished by the hydrogen carbonate (−HCO3)‐assisted concerted metalation‐deprotonation (CMD) process, not through the oxidative addition of Rh(I)‐catalyst. Meanwhile, our calculation results indicate that the regioselectivity of CH bond arylation of indole with anhydride can be attributed to the relative stability of the CMD transition states in the CH bond activation process. Moreover, in the CH activation step, the base (−HCO3) is not coordinated with the Rh center.