Efficient Allylation of Nucleophiles Catalyzed by a Bifunctional Heterogeneous Palladium Complex‐Tertiary Amine System

Abstract

AbstractWe demonstrate the synergistic catalysis of a silica‐supported diaminopalladium complex and a tertiary amine (SiO2/diamine/Pd/NEt2) as well as synthetic scope of the Tsuji–Trost reaction of 1,3‐dicarbonyls, phenols, and carboxylic acids with allyl carbonate and acetates. The synergistic catalysis of SiO2/diamine/Pd/NEt2 exhibited wide applicability and high activity for the Tsuji–Trost reaction. For example, the reaction of ethyl 3‐oxobutanate with allyl methyl carbonate afforded the allylated product in >99% yield at 70 °C for 5 h. The yield of allylated products was 26% for SiO2/diamine/Pd, without immobilization of the tertiary amine group. In the reaction of 1.0 mmol of ethyl 3‐oxobutanate using 0.60 μmol of Pd in SiO2/diamine/Pd/NEt2, the turnover number (TON) of Pd reached up to 1070 within 24 h. Phenols with electron‐withdrawing groups, such as nitro and chloro groups, on the para position resulted in high product yields. The SiO2/diamine/Pd/NEt2 catalyst was reusable at least 4 times without appreciable loss of its activity and selectivity in the reaction of p‐chlorophenol.