We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe–N_x and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe–N–C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.

中文翻译：

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一种双功能铁纳米复合催化剂，可将烯烃高效氧化为酮和1,2-二酮

我们在此报告了一种双功能铁纳米复合催化剂的制备，其中两个Fe–N _x催化活性位点磷酸铁和铁的氧化位和路易斯酸位同时被整合到一个分层的N，P-双掺杂多孔碳中。作为一种双功能催化剂，它具有良好的催化作用，可在较温和的反应条件下使用TBHP作为氧化剂，将烯烃直接氧化裂解为酮或将其氧化为1,2-二酮，具有广泛的底物范围，并具有较高的官能团耐受性。此外，可以很容易地将其回收以进行后续回收，而不会造成明显的活性损失。机理研究表明，烯烃的直接氧化是通过形成环氧化物作为中间体，然后进行酸催化的Meinwald重排而产生的，该酮的碳原子短了一个或亲核开环，从而以级联方式生成1,2-二酮。