作者:Anthony Millet、Paolo Larini、Eric Clot、Olivier Baudoin
DOI:10.1039/c3sc50428j
日期:——
We report a general palladium-catalyzed β-arylation of Boc-piperidines, which yields a variety of valuable 3-arylpiperidines in a simple and direct manner. The β- vs. α-arylation selectivity was controlled by the ligand, with flexible biarylphosphines providing mainly the desired β-arylated products whereas more rigid biarylphosphines mainly furnished the more classical α-arylated products. The computed reaction mechanism (DFT), studied from the common α-palladated intermediate, indicated that the reductive elimination steps leading to the α- and β-arylated products are selectivity-determining. Moreover, the experimental trend obtained with different ligands was well reproduced by the calculations.
我们报道了一种通用的钯催化Boc-哌啶的β-芳基化反应,该反应以简单直接的方式制备了多种有价值的3-芳基哌啶。通过配体的调控,灵活的双芳基膦配体主要提供了所需的β-芳基化产物,而更刚性的双芳基膦配体主要生成了传统的α-芳基化产物。通过计算反应机理(DFT),从常见的α-钯配合物中间体出发,研究结果表明α-和β-芳基化产物形成的还原消除步骤是选择性决定步骤。此外,不同配体的实验趋势在计算中得到了很好的再现。