Ketone Alkylation Using Simple Olefins: A Sustainable Chemistry Approach

在化学系化学合成(SYN)计划的支持下，芝加哥大学的董广斌教授带领一个研究团队发明了制造碳-碳键的新方法。碳-碳键是几乎所有有机化学品的重要组成部分。这些重要的键构成了大多数药物和塑料(聚合物)的主干，因此可以大规模生产。董？S博士的研究重点是从简单、廉价和无毒的原料中形成碳-碳键，而不会产生必须分离和/或丢弃的副产品。这种方法遵循绿色化学的原则。因为新的合成路线对大宗商品和特种化学品更加环保。研究补助金还支持对学生进行多层次的教育。董教授积极参与“Chis&Amp；E”计划，为芝加哥公立中学的学生提供早期化学教育。他还参与了教授高中生的大学生学者计划和为本科生提供实验室研究经验的领导力联盟暑期研究早期识别计划(SR-EIP)。这些推广活动鼓励不同群体的学生在学习的同时探索科学和工程领域的职业，并积极为研究做出贡献。该项目的目标是通过过渡金属(TM)催化的碳-氢(C-H)键激活开发无副产酮-烯烃偶联反应。这些方法可以作为获取烷基化酮的更环保的方法。该研究计划使用双功能模板来实现烯胺/TM或亚胺/TM协同催化。该团队的目标是：第一，通过烯胺/TM协同催化，开发酮与简单烯烃的直接分支选择性α-烷基化反应；第二，通过亚胺/TM协同催化，开发酮与简单烯烃的直接烷基化反应。羰基官能化在有机合成中起着核心作用。烯醇烷基化和共轭(烷基)加成是在羰基位置引入烷基的两种常见而重要的方法。值得注意的是，这些反应不是经济或环境友好的过程，主要是因为使用了化学计量的卤素烷基化试剂和/或化学计量的有机金属物种。在这里，董教授和他的团队使用TM催化的烯胺或亚胺介导的C-H官能化策略来实现酮的烷基化反应，使用简单的未活化的烯烃作为烷化剂。这种方法被认为比目前的方法更可持续，因为不会产生化学计量的副产物，反应条件通常是pH和氧化还原中性的，因此可以容忍广泛的官能团。从实用的角度来看，与相应的烷基卤化物或有机金属物种相比，烯烃通常是一种更便宜、更容易获得的原料。通过新型双功能催化剂开发了以正构烯烃为烷基化试剂的无副产酮烷基化方法。董教授和他的团队正在开展几项外展活动，包括向小学生介绍化学概念。将不同年龄段和不同背景的学生的教育活动整合到现有的研究计划中一直是研究小组的主要目标。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Supported by the Chemical Synthesis (SYN) Program in the Division of Chemistry, Professor Guangbin Dong of the University of Chicago is leading a team of researchers to invent new ways to make carbon-carbon bonds. Carbon-carbon bonds are an essential part of almost all organic chemicals. These important bonds form the backbone of most medicines and plastics (polymers) and thus are produced on massive scales. Dr. Dong?s research focuses on forming carbon-carbon bonds from simple, inexpensive and non-toxic stating materials without also producing by-products which must be separated and/or discarded. This approach follows the principles of ?Green Chemistry? in that the new synthetic routes to commodity and specialty chemicals are more environmentally friendly. The research grant also supports the education of students at many levels. Professor Dong is actively engaged in the "ChiS&E" program to provide early chemistry education to Chicago public middle-school students. He is also involved in the Collegiate Scholars Program to teach high school students and the Leadership Alliance Summer Research Early Identification Program (SR-EIP) to offer laboratory research experiences to undergraduate students. These outreach activities encourage a diverse group students to explore careers in science and engineering while learning and actively contributing to research.The goal of this project is to develop byproduct-free ketone-olefin coupling reactions via transition metal (TM)-catalyzed carbon-hydrogen (C-H) bond activation. These approaches could serve as more environmentally-friendly approaches to access alkylated ketones. The research plan employs bifunctional templates to enable enamine/TM or imine/TM cooperative catalysis. The team's objectives are first, to develop a direct branched-selective alpha-alkylation of ketones with simple olefins via enamine/TM cooperative catalysis and second, to develop a direct alkylation of ketones with simple olefins via imine/TM cooperative catalysis. Carbonyl functionalization plays a central role in organic synthesis. Enolate alkylation and conjugate (alkyl) addition represent two common and important approaches for introducing alkyl groups at carbonyl positions.. Notably, these reactions are not economically- or environmentally-friendly processes mainly due to the use of stoichiometric halogen-based alkylating agents and/or stoichiometric organometallic species. Here, Professor Dong and his team employ a TM-catalyzed enamine or imine-mediated C-H functionalization strategy to achieve ketone alkylation using simple unactivated olefins as the alkylating agents. This approach is considered more sustainable than current methods because stoichiometric by-products are not generated and the reaction conditions are generally pH- and redox-neutral, thereby tolerating a broad range of functional groups. From a practical viewpoint, olefins are typically a cheaper and more readily available feedstock than the corresponding alkyl halides or organometallic species. Byproduct-free ketone alkylation methods using regular olefins as the alkylating agents are developed through the new bifunctional catalysts. Professor Dong and his team are engaged in several outreach activities, including introducing grade school students to chemical concepts. Integrating educational activities of students from diverse age groups and backgrounds into the existing research program has been a primary goal of the research group.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.