Metal-organic frameworks (MOFs) are newly emerging and versatile platforms for designing catalysts, and catalytic oxidation of cyclohexene has attracted much academic and industrial attention for the versatile reactivity of the substrate and the great importance of the various oxygenated products. Here we report the bifunctional catalytic properties of a sulfonic-containing MOF, MIL-101-SO₃H, for cyclohexene oxidation. The sulfonic group and the Cr(III) site acts in a complementary or collaborative way. The Cr(III) framework promotes the oxidation to 3-hydroperoxycyclohex-1-ene (perox) and 2-cyclohexen-1-one (1-one) (route A), whereas the sulfonic group in collaboration with the Cr(III) framework promotes the oxidation to diol (route B) and also enhances further conversions in route A: from perox to 1-one, to 2-cyclohexen-1,4-dione (dione) and even to benzoquinone. With the bifunctional MOF, molecular oxygen alone cannot oxidize cyclohexene but participates as oxidant cooperating with tert-butyl hydroperoxide (TBHP) to accelerate the reactions and to alter the product distribution in favor of dione.

金属有机骨架（MOF）是用于设计催化剂的新兴且通用的平台，环己烯的催化氧化反应因底物的通用反应性和各种氧化产物的重要性而引起了学术界和工业界的广泛关注。在这里，我们报告含磺酸的MOF MIL-101-SO ₃的双功能催化性能H，用于环己烯的氧化。磺酸基团和Cr（III）位点以互补或协作的方式起作用。Cr（III）骨架促进氧化成3-氢过氧环己-1-烯（perox）和2-cyclohexen-1-one（1-one）（路线A），而磺酸基与Cr（III）协同作用骨架可促进氧化为二醇（途径B），并进一步提高途径A中的转化率：从过氧到1-one，再到2-cyclohexen-1,4-dione（二酮），甚至到苯醌。使用双功能MOF，分子氧本身无法氧化环己烯，但会与叔丁基氢过氧化物（TBHP）协同作为氧化剂参与，以加速反应并改变产物分布，有利于二酮。