Electronically nonsymmetric phenanthrolines (R≠ R′) give improved activities in the palladium-catalyzed carbonylation of nitrobenzene with respect to their symmetrical counterparts. This may be due to the detachment of the more weakly binding nitrogen during the rate-determining step of the reaction, as suggested by a previous mechanistic study.
![Malonic acid, [(8-quinolylamino)Methylene]-, cyclic isopropylidene ester (8CI) Structure](https://image.chemsrc.com/caspic/284/25063-76-7.png)