Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology , 43007, Tarragona, Spain.
Departament de Química and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès, Spain.
J Am Chem Soc. 2016 Oct 5;138(39):12747-12750. doi: 10.1021/jacs.6b07999. Epub 2016 Sep 22.
The use of the hypervalent iodine reagents in oxidative processes has become a staple in modern organic synthesis. Frequently, the reactivity of λ iodanes is further enhanced by acids (Lewis or Brønsted). The origin of such activation, however, has remained elusive. Here, we use the common combination of PhI(OAc) with BF·EtO as a model to fully explore this activation phenomenon. In addition to the spectroscopic assessment of the dynamic acid-base interaction, for the first time the putative PIDA·BF complex has been isolated and its structure determined by X-ray diffraction. Consequences of such activation are discussed from a structural and electronic (DFT) points of views, including the origins of the enhanced reactivity.
高价碘试剂在氧化过程中的应用已经成为现代有机合成的重要手段。通常，通过酸（路易斯酸或布朗斯特酸）可以进一步增强 λ-碘代烷的反应活性。然而，这种活化的起源仍然难以捉摸。在这里，我们使用 PhI(OAc)与 BF·EtO 的常见组合作为模型，来充分探索这种活化现象。除了对动态酸碱相互作用的光谱评估外，我们首次分离出了可能的 PIDA·BF 配合物，并通过 X 射线衍射确定了其结构。从结构和电子（DFT）的角度讨论了这种活化的后果，包括增强反应性的起源。
