Ligand and base additive effects on the reversibility of nucleophilic addition in palladium-catalyzed allylic aminations monitored by nucleophile crossover

摘要

A nucleophile crossover experiment was used to monitor the reversibility of nucleophilic addition of benzylamine to pi-allylpalladium complexes. Dppe, dppp, dppb, and PHOX showed more crossover than PPh3 and dppm in both DMF and dichloromethane. Crossover was inhibited by the addition of DBU or Cs2CO3, but much less elimination to diene side products was observed with Cs2CO3. Analysis of percent crossover vs. percent reaction completion using the PHOX ligand revealed that with added DBU or Cs2CO3 crossover only began occurring after 100% completion had been reached. (C) 2016 Elsevier Ltd. All rights reserved.