Boronic Acids for Transition Metal Free Organic Synthesis

用于合成有机（含碳）分子的新化学反应的发展在发现新药物和功能材料（例如液晶，发光二极管）方面发挥着核心作用。在过去的几十年里，涉及含过渡金属物种的此类反应大幅增加。虽然非常有用，但这些金属具有各种缺点，包括稀有（以及相关的高成本）和毒性。最近，在有机合成中，无金属方法受到了极大的关注，它现在在效率方面与许多基于金属的方法竞争，而没有相关的缺点。某些硼的有机化合物（硼酸及其衍生物）通常用作金属催化反应中的试剂，但很少用作催化剂本身，尽管它们具有许多有用的性质。这些优点包括相对低的毒性、对空气和水分的稳定性、低成本和它们的刘易斯酸性性质，这允许它们以独特的方式与某些底物（刘易斯碱）反应。我们利用这些性质中的一些来促进所谓的Friedel-Crafts反应，这是构建有用分子结构的重要过程。拟议的研究涉及进一步开发硼酸的独特性质，用作这些和其他重要过程的催化剂，包括环加成（成环）和重排反应。硼酸作为药物和材料化学试剂的普遍使用也促使我们开发新的制备方法。我们还将开发新的反应，涉及硼酸衍生物作为起始材料在无金属反应。这些反应中的几个导致硼基团保持完整的产物，提供与现有方法的协同作用，用于进一步转化该基团。这些新方法将使制备新的、有用的分子成为可能，这些分子很难或不可能通过其他方法制备。

The development of new chemical reactions for the synthesis of organic (carbon-containing) molecules plays a central role in the discovery of novel pharmaceuticals and functional materials (e.g. liquid crystals, light-emitting diodes). Past decades have seen a huge increase in such reactions involving transition-metal containing species. Although very useful, these metals have various drawbacks, including rarity (and associated high cost) and toxicity. Recently, significant attention has been paid to metal-free methods in organic synthesis, which now compete favourably in terms of efficiency with many metal-based methods without the associated disadvantages. Certain organic compounds of boron (boronic acids and their derivatives) are used commonly as reagents in metal catalysed reactions, but rarely as catalysts themselves, despite their many useful properties. These include relatively low toxicity, stability to air and moisture, low cost and their Lewis acidic nature which allows them to react in unique ways with certain substrates (Lewis bases). We have employed some of these properties to promote the so-called Friedel-Crafts reaction, which is an important process for the construction of useful molecular structures. The proposed research involves further exploitation of the unique properties of boronic acids for use as catalysts in these and other important processes, including cycloaddition (ring-forming) and rearrangement reactions. The common use of boronic acids as reagents for medicinal and materials chemistry has also prompted us to develop new methods for their preparation. We will also develop new reactions involving boronic acid derivatives as starting materials in metal free reactions. Several of these reactions lead to products where the boron group remains intact, providing synergy with existing methods for further transformation of this group. These new methods will enable the preparation of new, useful molecules that would be difficult or impossible to prepare by other means.**