Room-Temperature Benzylic Alkylation of Benzylic Carbonates: Improvement of Palladium Catalyst and Mechanistic Study
作者:Ryoichi Kuwano、Masashi Yokogi、Ken Sakai、Shigeyuki Masaoka、Takashi Miura、Sungyong Won
DOI:10.1021/acs.oprd.9b00210
日期:2019.8.16
nucleophilic substitution of benzyl carbonates was improved by using 1,1′-bis(diisopropylphosphino)ferrocene (DiPrPF) as the ligand. The [Pd(η3-C3H5)(cod)]BF4–DiPrPF catalyst allows the benzylic substitution with soft carbanions to proceed even at 30 °C, affording the desired products in high yields (up to 99% yield). Thermally unstable pyridylmethyl esters are employable as the electrophilic substrates
为苄基碳酸酯的亲核取代的钯催化剂是通过使用1,1'-双(二异丙基)二茂铁(d改善我配体PrPF)为。的[将Pd(η 3 -C 3 H ^ 5)(COD)] BF 4 -D我PrPF催化剂允许与软碳负离子苄基取代,甚至在30℃下进行,得到高产率的所需产物(高达99%屈服)。热不稳定的吡啶基甲基酯可用作亲电底物,用于用改进的催化剂进行苄基烷基化。此外,我们研究了通过D i PrPF配体催化苄基烷基化的机理。钯(0)配合物D iPrPF在室温下激活苄基C–O键以形成(苄基)钯(II)中间体。苄基配体的配位模式将是η之间的平衡1 -和η 3 -manner。亲核试剂将优先与η反应3 -苄基配体,得到所需产物。