CAREER: SusChEM: New Methods for Heterocycle Synthesis via Organic Photoredox Catalysis

在这个由NSF化学部化学合成计划资助的项目中，查佩尔山的北卡罗来纳州大学的大卫尼斯维奇教授正在开发新的高效化学反应，用于合成在治疗学中具有潜在应用的小环状有机分子。 收集可见光的有机染料被用作催化剂，用于从容易获得和可再生的化学品开发这些新的和广泛适用的合成转化。 通过了解与单电子氧化还原化学相关的氧化还原电位，可以改进这些染料和催化剂的适当选择。 Nicewicz博士和他的学生正在收集和规范化有机电化学氧化还原数据，这些数据将作为有机，有机金属和无机化学从业者参考数据的有用纲要。 该奖项的更广泛影响还包括对莫尔黑德天文馆科学中心的公众宣传。 Nicewicz教授与天文馆的工作人员合作，设计和开发针对中学生的“烹饪化学”。 SciVentures计划的重点是乳液，酵母和二氧化碳，发酵，酸和碱的化学，让年轻人接触到厨房里容易获得的化学概念。由吖啶鎓盐和氧化还原活性氢原子供体组成的新型双组分有机光氧化催化剂体系能够实现几种新类型的杂环形成转化。通过该方法形成的杂环的种类包括来自烯烃和丰富的化学原料如不饱和醇、羧酸、胺和酰胺的环醚、内酯、吡咯烷和内酰胺，而不需要预官能化。 这种无金属的双催化剂体系为合成有机化学的实践者提供了新的工具。 本提案中开发的新反应技术应用于双降三萜类化合物rubriflodilactone B（一种具有抗HIV-1活性的分子）的首次全合成。

In this project funded by the Chemical Synthesis Program of the NSF Chemistry Division, Professor David Nicewicz of The University of North Carolina at Chapel Hill is developing new and highly efficient chemical reactions for the synthesis of small cyclic organic molecules that have potential applications in therapeutics. Purely organic dyes that harvest visible light are used as catalysts in the development of these new and widely applicable synthetic transformations from readily available and renewable chemicals. The appropriate selection of these dyes and catalysts is improved by knowledge of the redox potentials associated with single electron redox chemistry. Dr. Nicewicz and his students are assembling and normalizing organic electrochemical redox data that will serve as a useful compendium of reference data for practitioners of organic, organometallic and inorganic chemistries. The broader impacts of this award also include public outreach to the Morehead Planetarium Science Center. Professor Nicewicz collaborates with Planetarium staff to design and develop "The Chemistry of Cooking" targeted towards middle school students. The SciVentures Program focuses on the chemistries of emulsions, yeast and carbon dioxide, fermentation, and acids and bases exposing young people to the readily accessible chemistry concepts in the kitchen. A novel two-component organic photooxidation catalyst system comprised of an acridinium salt and redox-active hydrogen atom donor enables several new classes of heterocycle-forming transformations. The classes of heterocycles forged by this method include cyclic ethers, lactones, pyrrolidines and lactams from alkenes and abundant chemical feedstocks such as unsaturated alcohols, carboxylic acids, amines and amides without the need for pre-functionalization. This metal-free dual catalyst system provides new tools to practioners of synthetic organic chemistry. The new reaction technology developed in this proposal is applied to the first total synthesis of the bisnortriterpenoid, rubriflordilactone B, a molecule with documented activity against HIV-1.