Ketone Alkylation Using Simple Olefins: A Sustainable Chemistry Approach

在化学系化学合成项目的支持下，芝加哥大学的董广斌教授正在研究基于催化剂的新策略，以实现从酮类和烯烃类化合物的简单前体中产生无副产物的增值产品。酮是一类广泛存在的有机分子，在化学制造中有许多应用；然而，现有的衍生这些材料的方法通常需要昂贵和/或腐蚀性试剂，并导致大量废物流的产生。为了克服这些问题，Dong研究小组正在开发环境上可持续的酮衍生化方法，使其能够使用特别设计的催化剂和简单的烯烃（廉价的商品化学品）的组合直接获得一系列有用的产品。董教授和他的同事参与了一些拓展活动，例如为芝加哥公立中学生提供早期化学教育的“ChiS&amp；E”计划，以及允许高中生参与实验室研究的“大学学者计划”，这些活动带来了更广泛的社会效益。这些活动将鼓励人口多样化的年轻人，其中许多人属于科学、技术、工程和数学（STEM）领域代表性不足的群体，在学习和/或积极参与研究的同时探索科学和工程职业。该资助研究的目标是通过过渡金属催化的碳氢功能化来开发α和β选择性酮-烯烃偶联反应。为了实现第一个过程，将利用Lewis酸/过渡金属协同催化，以简单的烯烃作为偶联伙伴，实现酮底物的直接烷基化。为了实现第二个过程，酮的β -烷基化，同样由烯烃，将通过过渡金属催化的脱饱和氢化物转移策略进行探索。采用炔的类似方法也将被用于实现-烯基化。从基础和实际的角度来看，这些方法的优点是显著的，因此：(1)潜在地避免了化学计量副产物；(2)反应条件一般为pH-和氧化还原中性，因此可耐受广泛的官能团；而且，(3)烯烃通常比相应的烷基卤化物或有机金属更便宜，更容易获得的原料。最终，预计将从这些研究中出现一套操作方便且环境可持续的羰基烷基化方法，并且这些发现将代表双功能和串联催化领域的重要进展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Synthesis program in the Division of Chemistry, Professor Guangbin Dong of the University of Chicago is studying new catalyst-based strategies to achieve the byproduct-free generation of value-added products from simple precursors of the ketone and olefin compound classes. Ketones are a widespread class of organic molecules that have many applications in chemical manufacturing; however, established methods to derivatize these materials typically require expensive and/or corrosive reagents and lead to the generation of significant waste streams. To overcome such issues, the Dong Research Group is developing environmentally sustainable approaches for the derivatization of ketones that enable direct access to a range of useful products using a combination of specially designed catalysts and simple olefins (inexpensive commodity chemicals). The broader impacts of the funded project extend to societal benefits accrued by the participation of Professor Dong and his coworkers in outreach activities, such as the "ChiS&E" program which provides early chemistry education to Chicago public middle-school students, and the Collegiate Scholars Program which allows for high school students to become involved in laboratory research. These activities will encourage a demographically diverse pool of young people, many of whom belong to groups underrepresented in science, technology, engineering, and mathematics (STEM) fields, to explore careers in science and engineering while learning and/or actively contributing to research.The goal of the funded research is to develop both alpha- and beta-selective ketone-olefin coupling reactions via transition metal-catalyzed C-H functionalization. To achieve the first process, Lewis acid/transition metal cooperative catalysis will be utilized to enable direct alpha-alkylation of the ketone substrates with simple olefins as coupling partners. To realize the second process, beta-alkylation of ketones, again by olefins, will be explored via a transition metal-catalyzed desaturation-based hydride-transfer strategy. An analogous process employing alkynes will likewise be pursued to achieve beta-alkenylation. The merits of these approaches are significant from both fundamental and practical standpoints, thus: (1) stoichiometric byproducts are potentially avoided; (2) the reaction conditions are generally pH- and redox-neutral, thereby tolerating a broad range of functional groups; and, (3) olefins are typically less expensive and more readily available feedstocks than the corresponding alkyl halides or organometallic species. Ultimately, it is anticipated that a suite of operationally convenient and environmentally sustainable carbonyl alkylation methods will emerge from these studies and that the findings will represent important advances to the fields of bifunctional and tandem catalysis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.