Palladium-Catalyzed Alkyl Amination of Olefins via Radical-Polar Crossover at Room Temperature

by Anurag Singh, Kuntal Pal, Sayan Dutta, Arnab Dey, Rajesh Kancherla, Bholanath Maity, Luigi Cavallo, Magnus Rueping
Year: 2025 DOI: https://doi.org/10.1002/anie.202503446

Abstract

In contrast to traditional ground-state palladium catalyzed alkyl Heck reactions, which are thermodynamically unfavourable and endothermic, excited-state palladium catalysis facilitates single-electron mechanisms, with light primarily driving the formation of alkyl radicals from triplet-state Pd(0). Here, we report a novel and mechanistically distinct Pd-catalyzed reaction, where the key hybrid alkyl Pd(I)-radical intermediate is generated from the triplet-state Pd(II) at room temperature. This hybrid species engages in the addition to dienes and conjugated enynes, producing a transposed open-shell allyl Pd(I)-radical, which undergoes radical-polar crossover (RPC) to yield the desired alkyl amination products. Density functional theory (DFT) studies offer insights into the reaction mechanism, confirming the involvement of hybrid alkyl/allyl Pd(I) radical species as key intermediates.