Cooperative Interplay of Bronsted Acid and Lewis Acid Sites in MIL-101(Cr) for Cross-Dehydrogenative Coupling of C-H Bonds
Cooperative Interplay of Bronsted Acid and Lewis Acid Sites in MIL-101(Cr) for Cross-Dehydrogenative Coupling of C-H Bonds
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MIL-101(Cr) 中布朗斯台德酸和路易斯酸位点的协同相互作用用于 C-H 键的交叉脱氢偶联
DOI：
10.1021/acsami.0c20369
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发表时间：
2021-03-02
影响因子：
9.5
通讯作者：
Zhang, Zhiguo
中科院分区：
文献类型：
--
作者：
Chen, Jingwen;Zhang, Yuanyuan;Zhang, Zhiguo
交叉脱氢偶联(CDC)是化学合成中碳-碳键形成的有效工具。本文报道了一种具有双Lewis酸性铬中心和双磺酸中心的金属-有机骨架(MIL-101(Cr)-SO3H)，作为一种有效的催化材料，可用于以O-2为氧化剂直接交叉偶联不同的亲核试剂。MIL-101(Cr)-SO3H的高度多孔结构使反应物能够自由进入MOF孔内的催化活性中心。动力学研究表明，MOF上的铬中心加速了黄原烯的限速自氧化反应，与MOF配体上的磺酸基团协同促进了CDC反应。此外，该催化体系还表现出良好的官能团相容性，合成了多种有价值的黄原烯衍生物，产率令人满意。此外，MIL-101(Cr)-SO3H催化剂可重复使用，连续运行6次后仍保持其催化活性和晶体结构。
Cross-dehydrogenative coupling (CDC) is an effective tool for carbon-carbon bond formation in chemical synthesis. Herein, we report a metal-organic framework (MOF) possessing dual Lewis acidic Cr sites and sulfonic acid sites (MIL-101(Cr)-SO3H) as an efficient catalytic material for direct cross-coupling of xanthene and different nucleophiles using O-2 as the oxidant. The highly porous structure of MIL-101(Cr)-SO3H enables the free access of reactants to the catalytic active sites inside MOF pores. Kinetic studies indicated that the Cr sites of MOF accelerate the rate-limiting autoxidation reaction of xanthene, which synergistically work with the sulfonic acid group on MOF ligands in promoting the CDC reactions. Besides, the catalytic system shows excellent functional group compatibility, and a variety of valuable xanthene derivatives were synthesized with satisfactory yields. Furthermore, MIL-101(Cr)-SO3H can be reused and its catalytic activity and crystal structure remain after six consecutive runs.