Exploration of novel paradigms in metal-free catalysis

在过去几年中，人们对设计新的绿色技术以取代主要依赖昂贵和有毒的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专注于使用贱金属，而不是第二和第三行过渡元素（铑，铱，铂，钯）。另一种有希望的方法包括使用受抑刘易斯对（FLP），这是道格拉斯Stephan命名的流行概念，用于解释刘易斯对作为无金属催化剂由于空间或几何约束而不能形成加合物的反应性。这些物种可以为目前的工业技术提供廉价、绿色和无毒的替代品。我们在两亲分子（在骨架中同时具有刘易斯酸和刘易斯碱性部分的分子）的合成和反应性方面的10年经验使我们能够对无金属催化剂有独特的看法。基于我们最近在FLP催化中报道的一些重要结果和我们对有机金属催化的了解，我们提出了三个假设，这些假设将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刘易斯酸度和碱度的FLP，以用作工业相关应用中的催化剂。* 我们在本提案中提议研究的转化是合成化学和制药工业中最有用的转化之一。它将包括羰基部分还原成醇，芳烃和烷烃的催化C-H键官能化，以及炔的氢胺化。本提案中提出的概念的演示将允许社区将FLP用于许多其他催化过程，并使该技术成为2-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. **