Dohi Toshifumi
College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
Chem Pharm Bull (Tokyo). 2010 Feb;58(2):135-42. doi: 10.1248/cpb.58.135.
Oxidation reactions consist of a number of important transformations in organic synthesis. However, in spite of their utility in both laboratory- and industrial-scale production, oxidations are among the most problematic processes regarding the factors of safety, environmental friendliness, operational simplicity, etc. As oxidants, hypervalent iodines, such as phenyliodine(III) diacetate (PIDA) and phenyliodine(III) bis(trifluoroacetate) (PIFA), are among promising reagents for developing environmentally benign oxidation reactions due to their low toxicities, mild reactivity, ready availability, high stability, and easy handling. Our research objective is, largely in consideration of economic and environmental viewpoints, to enhance the synthetic values of these reagents as useful alternatives to highly toxic heavy-metal oxidants and even rare transition metals by pioneering their efficient utilization methods and unique reactivities. During this study, we have succeeded in the development of new recyclable reagents 1 and their catalytic utilization, and the design of a new chiral reagent 2 and its application to perform asymmetric oxidations. Accordingly, the recycling and catalytic use of a hypervalent iodine reagent became possible in many representative types of oxidative bond-forming reactions, some of which even include key transformations for natural product synthesis. A summary of these important achievements in hypervalent iodine chemistry are described in this review.
氧化反应在有机合成中包含许多重要的转化过程。然而，尽管氧化反应在实验室规模和工业规模生产中都有其用途，但在安全、环境友好性、操作简便性等方面，氧化反应却是最具问题的过程之一。作为氧化剂，高价碘，如二醋酸碘苯(III)（PIDA）和双（三氟乙酸）碘苯(III)（PIFA），由于其低毒性、温和的反应性、易于获得、高稳定性和易于处理，是开发环境友好型氧化反应的有前景的试剂。我们的研究目标主要是从经济和环境的角度出发，通过开创这些试剂的有效利用方法和独特反应性，提高它们作为剧毒重金属氧化剂甚至稀有过渡金属的有用替代品的合成价值。在这项研究中，我们成功开发了新型可循环试剂1及其催化应用，设计了新型手性试剂2并将其应用于不对称氧化反应。因此，高价碘试剂在许多代表性的氧化成键反应中实现了循环利用和催化使用，其中一些反应甚至包括天然产物合成的关键转化过程。本文综述了高价碘化学中的这些重要成果。
