Mechanistic insights into Ni-assisted homolytic substitution in alkylgermylation: A theoretical study

Chlorogermanes have emerged as significant electrophilic germane reagents for the construction of C Ge bonds through transition-metal-catalyzed coupling strategies. Chlorogermanes are typically activated through oxidative addition in nickel-catalyzed coupling reactions. The computational evidence presented in this report demonstrates a novel Ni-assisted bimolecular homolytic substitution activation mode, which is more favorable than either oxidative addition or bimolecular nucleophilic substitution. In addition, DFT calculations shed light on the reaction mechanism and reactivity. To investigate electron transfer during the key step, we performed intrinsic reaction coordinate (IRC) calculations on the transition state of the Ni-assisted bimolecular homolytic substitution. The present work was undertaken to construct a theoretical framework for the rational design of experiments targeting germylation via transition-metal catalysis. A novel Ni-assisted bimolecular homolytic substitution activation mode (S H 2) during the Pd-catalyzed alkylgermylation of alkenes was proposed and investigated by DFT calculations. It was found that Ni-assisted S H 2 is lower in free energy compared to oxidative addition and bimolecular nucleophilic substitution. The activation mode of chlorogermanium is effectively expanded, facilitating further development in transition-metal-catalyzed cross-coupling germylation reactions.