New Frontiers in Transition Metal Free Synthesis

点击翻译按钮获取中文摘要

For many years chemists have been using chemical reactions to build complex molecules for an array of diverse applications ranging from drugs and agrochemicals to polymers and new materials as well as many, many others. In particular, reactions that create new carbon-carbon and carbon-heteroatom bonds have been particularly useful and scientists have commonly used catalysts based on transition metals to help them achieve this goal. These catalysts have undoubtedly revolutionised many branches of chemistry by allowing previously inaccessible scaffolds to be prepared. Despite their general utility, many chemists would prefer not to use these metals if possible. There are a number of reasons for this. Firstly, transition metals are often rare and expensive. This naturally leads to an expensive reaction, especially if undertaken on an industrial scale. Furthermore, many transition metal catalysts also require complex ligands that themselves are expensive and require prior synthesis. Occasionally, the ligand can even be more complex and more difficult to prepare than the target molecule. Chemists are therefore always interested in finding new and efficient ways of preparing complex molecules A second consideration for scientists employing transition metals is their toxicity. Many of these substances and their compounds are also toxic and extreme effort is required to remove all traces of them from the reaction products. These products are frequently drug molecules and naturally must meet strict safety regulations. Any process that can be developed where such catalysts are eliminated is therefore desirable, however very few have achieved this goal so far. This proposal seeks to address the above issues and develop new processes that create new carbon-carbon and carbon-heteroatom bonds but without employing transition metals. The work will build on the preliminary work from our own laboratory which suggests that simple bases, some of them known for centuries have a fascinating additional dimension to their personality. We aim to both study and exploit the reactivity of these simple compounds in order to engineer new methods of constructing complex products. In doing so we hope to find out more about these simple compounds and so alert others to the untapped potential that they might offer in developing clean, efficient and economical chemical processes.