Polystyrene-Cross-Linking Triphenylphosphine on a Porous Monolith: Enhanced Catalytic Activity for Aryl Chloride Cross-Coupling in Biphasic Flow
Polystyrene-Cross-Linking Triphenylphosphine on a Porous Monolith: Enhanced Catalytic Activity for Aryl Chloride Cross-Coupling in Biphasic Flow
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DOI：
10.1021/acs.iecr.0c02404
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发表时间：
2020-08-26
影响因子：
4.2
通讯作者：
Miura, Yoshiko
中科院分区：
文献类型：
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作者：
Matsumoto, Hikaru;Hoshino, Yu;Miura, Yoshiko
用于连续流动催化剂的固定化过渡金属非常需要实现自动化，放大，易于分离，再生和节能生产，具有高水平的可持续性和效率。在这里，我们报告了一个叔膦固定在大孔整料（M-PS-TPP）的具有挑战性的Pd催化的交叉偶联反应的芳基氯在连续流动系统。以高内相乳液（HIPE）为模板，采用本体聚合法制备了M-PS-TPP的整体和大孔结构。由于大孔径和高孔隙率，M-PS-TPP显示出对移动的相连续流动的高渗透性。在连续流动的Suzuki-Miyaura交叉偶联反应中，含无机盐的有机/水介质通过载钯整体柱（M-PS-TPP-Pd），没有严重堵塞。通过控制M-PS-TPP-Pd的配位化学和流体力学，促进了高活性膦-金属配合物的形成和反应物的快速传质。事实上，M-PS-TPP-Pd柱在连续流动条件下的产率（类似于93%）和周转数（2704）比间歇条件下的产率（类似于6%）高得惊人。
Immobilized transition metals for continuous-flow catalyses are greatly in demand to achieve automation, scale-up, facile separation, regeneration, and energy-saving production with high level of sustainability and efficiency. Here, we report a tertiary phosphine immobilized on a macroporous monolith (M-PS-TPP) for the challenging Pd-catalyzed cross-coupling reaction of aryl chloride in a continuous-flow system. The monolithic and macroporous structure of M-PS-TPP was fabricated by bulk polymerization in the presence of a high internal phase emulsion (HIPE) template. Owing to the large pore size and high porosity, the M-PS-TPP showed high permeability against continuous flow of the mobile phase. The continuous-flow Suzuki-Miyaura cross-coupling reaction was realized by permeation of organic/aqueous media containing inorganic salt through a Pd-loaded monolith (M-PS-TPP-Pd) column without serious clogging. Controlling coordination chemistry and hydrodynamics of M-PS-TPP-Pd boosted highly active phosphine-metal complex formation and fast mass transfer of reactants. Indeed, the M-PS-TPP-Pd column showed surprisingly higher yields (similar to 93%) and turnover numbers (2704) under continuous-flow conditions than that under batch conditions (similar to 6%).