Exploration of novel paradigms in metal-free catalysis

在过去的几年里，人们对设计新的绿色技术来取代主要依赖昂贵和有毒贵金属的催化系统产生了极大的兴趣。因此，大多数研究人员一直将他们的工作重点放在贱金属上，而不是第二和第三排过渡元素(Rh、Ir、铂、Pd)。另一种有希望的方法是使用受挫Lewis对(FLP)，这是道格拉斯·斯蒂芬(Douglas Stephan)提出的一个流行概念，用来解释Lewis对的反应活性，因为空间或几何约束阻止了Lewis对形成加合物，作为无金属催化剂。这些物种可以为当前的工业技术提供廉价、绿色和无毒的替代品。*我们在双亲分子(框架中同时具有Lewis酸和Lewis碱性部分的分子)的合成和反应方面的10年经验使我们能够对无金属催化有独特的看法。基于我们最近报道的FLP催化的一些重要结果和我们对有机金属催化的认识，我们提出了三个假说来指导高效无金属催化剂的开发。我们的计划涉及使用这些范例，在计算工作的帮助下，设计和合成具有定制的Lewis酸碱性的Flp，以用作工业相关应用中的催化剂。*我们在本提案中建议研究的转化是合成化学和制药行业中最有用的转化之一。它将包括将羰基部分还原为醇，芳烃和烷烃的催化C-H键官能化，以及炔烃的氢胺化。这项提案中提出的概念的展示将使社区能够将氟氯烃用于许多其他催化过程，并使这项技术成为双电子转移过程中过渡金属的可行替代品。**

There has been great interest in the past few years in the design of novel and green technologies to replace catalytic systems that rely mainly on expensive and toxic noble metals. As such, most researchers have been focusing their work on using base metals rather than second- and third-row transition elements (rhodium, iridium, platinum, palladium). Another promising approach consists of using Frustrated Lewis Pair (FLPs), a popular concept termed by Douglas Stephan to explain the reactivity of Lewis pairs prevented from forming adducts by steric or geometric constraints, as metal-free catalysts. These species can provide cheap, green and non-toxic alternatives to current industrial technologies.***Our 10-year experience in the synthesis and reactivity of ambiphilic molecules (molecules having both Lewis acid and Lewis basic moieties in the framework) allows us to have a unique look on metal-free catalysis. Based on some important results we reported recently in FLP catalysis and on our knowledge of organometallic catalysis, we propose three hypotheses that will guide the development of efficient metal-free catalysts. Our program involves using these paradigms, with the help of computational work, to design and synthesize FLPs with tailored Lewis acidity and basicity to use as catalyst in industrially-relevant applications. ***The transformations that we propose to investigate in this proposal are amongst the most useful in synthetic chemistry and in the pharmaceutical industry. It will include the reduction of carbonyl moieties to alcohols, the catalytic C-H bond functionalization of arenes and alkanes, and the hydroamination of alkynes. The demonstration of the concepts presented in this proposal will allow the community to use FLPs for many other catalytic processes and make this technology a viable replacement for transition metals in 2-electron transfer processes. **