Generating Active “L-Pd(0)” via Neutral or Cationic π-Allylpalladium Complexes Featuring Biaryl/Bipyrazolylphosphines: Synthetic, Mechanistic, and Structure–Activity Studies in Challenging Cross-Coupling Reactions
作者:A. J. DeAngelis、Peter G. Gildner、Ruishan Chow、Thomas J. Colacot
DOI:10.1021/acs.joc.5b01005
日期:2015.7.2
are efficient for a wide array of challenging C–C and C–X (X = heteroatom) cross-coupling reactions. Their high activity is correlated to their facile activation to a 12-electron-based “L-Pd(0)” catalyst under commonly employed conditions for cross-coupling reactions, noninhibitory byproduct release upon activation, and suppression of the off-cycle pathway to form dinuclear (μ-allyl)(μ-Cl)Pd2(L)2 species
已经开发出两类新的高活性但空气和水分稳定的π-R-烯丙基钯铝配合物,它们含有庞大的配体范围宽的联芳基和联吡唑基膦。中性π-烯丙基铝络合物结合了一系列联芳基/联吡唑基膦配体,而阳离子支架则容纳了非常庞大的配体。这些络合物在温和条件下很容易被活化,并且对于一系列具有挑战性的C–C和C–X(X =杂原子)交叉偶联反应非常有效。它们的高活性与它们在常见的交叉偶联反应条件下易于活化为基于12电子的“ L-Pd(0)”催化剂,活化时释放非抑制性副产物以及抑制向形式双核(μ-烯丙基)(μ-Cl)Pd 2(L)2种,受结构(单晶X射线)和动力学研究的支持。低催化剂含量和短反应时间的广泛的C–C和C–X偶联反应突出了这些催化剂在有机合成中的多功能性和实用性。