The aminophosphine-based pincer complexes [C6H3-2,6-NHP(piperidinyl)2}2Pd(Cl)] (2) and [C6H3-2,6-OP(piperidinyl)2}2Pd(Cl)] (3) are readily prepared from cheap starting materials by
sequential addition of 1,1?,1?-phosphinetriyltripiperidine and 1,3-diaminobenzene or resorcinol to solutions of [Pd(cod)(Cl)2] (cod = cyclooctadiene) in toluene under N2 in 'one pot'. Compounds 2 and 3 proved to be not only excellent catalysts
for the Suzuki and the Heck cross-coupling reactions, but they are also very convenient to use: The toluene solutions of the 'one-pot' syntheses can be used directly for the catalytic reactions, thereby saving the time-consuming isolation of the catalysts. The Suzuki cross-coupling reaction
catalyzed by 2 and 3 can be performed in air at 100 °C in toluene of technical quality: in the presence of only 0.001mol% of catalyst, several electronically deactivated and sterically hindered aryl bromides are quantitatively coupled with phenylboronic acid within a few
minutes of reaction time. Furthermore, complex 2 enables the use of activated and non-activated aryl chlorides as coupling partners in the Suzuki reaction. Compounds 2 and 3 have also been shown to be highly active and reliable Heck catalysts: Very low catalyst loadings
and short reaction times are required for the quantitative coupling of several electronically deactivated and sterically hindered aryl bromides with various olefins at 140 °C. At increased temperatures, even electronically deactivated and sterically hindered aryl chlorides can be efficiently
coupled with olefins in the presence of only 0.01 mol% of catalyst.
基于氨基膦的夹环配合物[C6H3-2,6-NHP(哌啶基)2}2Pd(Cl)](2)和[C6H3-2,6-OP(哌啶基)2}2Pd(Cl)](3)可以通过将1,1',1''-膦三哌啶和1,3-二氨基苯或间苯二酚依次加入苯甲醛溶液中[Pd(cod)(Cl)2](cod = 环辛二烯)在N2气氛下在甲苯中进行'一锅法'合成而得。化合物2和3不仅被证明是苏酞基和赫克交叉偶联反应的优秀催化剂,而且它们也非常方便使用:'一锅法'合成的甲苯溶液可以直接用于催化反应,从而节省了耗时的催化剂分离过程。由2和3催化的苏酞基交叉偶联反应可以在技术质量的甲苯中在空气中以100°C进行:在只有0.001mol%催化剂存在的情况下,几种电子失活和立体位阻的芳基溴化物可以在几分钟内与苯硼酸定量偶联。此外,化合物2使得在苏酞基反应中可以使用活化和非活化的芳基氯化物作为偶联伙伴。化合物2和3也被证明是高活性和可靠的赫克催化剂:在140°C下,对于几种电子失活和立体位阻的芳基溴化物与各种烯烃的定量偶联,需要非常低的催化剂负载和短的反应时间。在提高的温度下,即使是电子失活和立体位阻的芳基氯化物也可以在只有0.01mol%催化剂存在的情况下与烯烃高效偶联。