<i>In Situ</i> Formation of Cationic π-Allylpalladium Precatalysts in Alcoholic Solvents: Application to C–N Bond Formation
作者:Philippe Steinsoultz、Aurélien Bailly、Patrick Wagner、Estefania Oliva、Martine Schmitt、Laurence Grimaud、Frédéric Bihel
DOI:10.1021/acscatal.1c04641
日期:2022.1.7
report an efficient Buchwald–Hartwig cross-coupling reaction in alcoholic solvent, in which a low catalyst loading showed excellent performance for coupling aryl halides (I, Br, and Cl) with a broad set of amines, amides, ureas, and carbamates under mild conditions. Mechanistically speaking, in a protic and polar medium, extremely bulky biarylphosphine ligands interact with the dimeric precatalyst
我们报告了一种在醇溶剂中进行的高效 Buchwald-Hartwig 交叉偶联反应,其中低催化剂负载量显示了芳基卤化物(I、Br 和 Cl)与多种胺、酰胺、脲和氨基甲酸酯在条件温和。从机理上讲,在质子和极性介质中,极其庞大的联芳基膦配体与二聚体预催化剂 [Pd(π-( R )-allyl)Cl] 2相互作用形成相应的阳离子配合物 [Pd(π-( R )-allyl) (L)]Cl原位并且自发地。所得预催化剂在碱性条件下进一步演化为相应的 L-Pd(0) 催化剂,该催化剂通常用于交叉偶联反应。这项机理研究强调了醇类溶剂在活性催化剂形成中的突出作用。