CAREER: CAS: An Electrochemical Approach for Catalytic Dehydration

在化学系化学催化项目的支持下，宾夕法尼亚州立大学的Eric Nacsa正在研究由电能驱动的新型化学催化剂的开发，以促进脱水反应。药品、纺织品、塑料、食品和香水的发现和制造在很大程度上依赖于化学脱水。这些过程结合了更简单的前体，通过去除一个水分子来制造有用的产品，但为了实现这个看似简单的结果，它们压倒性地产生了大量不必要的、潜在浪费的化学副产品。电能被用来为催化剂提供动力，以一种概念上的新方式实现这些脱水反应，从而减少化学副产物的形成。Nacsa博士也在研究一种新的教学方法，旨在提高本科有机化学的学习成果和公平性。这门课程是医生、牙医、兽医和一系列工程师的先决条件，但它往往是这些职业的绊脚石，被认为是令人生畏和不公平的。这些问题正在通过发展新的评价方法来解决，作为考试密集型评价方法的替代办法。传统上，高效脱水催化剂的开发一直具有挑战性，因为在整个催化循环中需要抵消电子需求。Nacsa研究小组正在解决这一挑战，他们使用电化学来调节硫基有机催化剂的氧化状态。催化剂有望使酸的亲核取代产生酯和酰胺，醇的亲核添加产生醚、烷基卤化物和胺，利用电化学促进催化剂的活化和周转。通过避免通常与脱水反应相关的化学计量副产物的产生，这些类型的反应的环境足迹影响有望减少，衍生化过程有望简化，以支持广泛的发现和过程化学。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 Catalysis Program in the Division of Chemistry, Eric Nacsa of the Pennsylvania State University is studying the development of new chemical catalysts powered by electrical energy to promote dehydration reactions. The discovery and manufacture of medicines, textiles, plastics, food products, and perfumes depend heavily on chemical dehydrations. These processes combine simpler precursors to make useful products by removing a molecule of water, but they overwhelmingly generate a significant amount of unnecessary and potentially wasteful chemical byproduct to achieve this seemingly simple outcome. Electrical energy is being leveraged to power catalysts that achieve these dehydration reactions in a conceptually new manner that mitigates chemical byproduct formation. Dr. Nacsa is also studying a new teaching method that aims to improve learning outcomes and equity in the context of undergraduate organic chemistry. This course is a prerequisite for physicians, dentists, veterinarians, and a range of engineers, but it often presents a stumbling block to these careers that is seen as intimidating and inequitable. These issues are being addressed through the development of new types of assessments as alternatives to exam-intensive evaluation approaches.Efficient dehydration catalysts have traditionally been challenging to develop because of countervailing electronic demands throughout catalytic cycles. This challenge is being addressed by the Nacsa research team by using electrochemistry to modulate the oxidation state of sulfur-based organocatalysts. The catalysts are expected to enable nucleophilic substitutions of acids to afford esters and amides, and nucleophilic additions of alcohols to afford ethers, alkyl halides, and amines using electrochemistry to promote catalyst activation and turnover. By avoiding the generation of stoichiometric byproducts usually associated with dehydration reactions, the environmental footprint impact of these types of reactions is expected to be reduced, and the derivatization process is expected to be streamlined in support of a broad array of both discovery and process chemistries.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.