Novel Synthetic Methods

通过这一奖项，美国国家科学基金会化学部的化学合成计划支持了Gevorgyan教授的研究。他的研究团队正在开发新的方法，将丰富而廉价的原料转化为附加值产品。有机分子中大量存在的碳氢键是进行有用阐述的目标。然而，碳氢键的高强度防止了其容易断裂，因此可能需要强制条件，如高反应温度，或使用贵重和稀有的过渡金属。这样的化学也可能需要使用高度不稳定的试剂，这会引起安全问题。Gevorgyan教授的团队正在研究非常温和和安全的无过渡金属方法，以在可见光照射下从简单和稳定的前体生成和操作各种活性物种。这种方法允许温和、有效和选择性地使有机分子官能化。该项目的更广泛影响包括为构建化学生物学和材料科学中重要的积木分子提供了新的有效途径。此外，本研究有可能显著降低所需化学试剂的成本，从而对工艺效率和经济性产生有利影响。此外，Gevorgyan博士正在积极参与招募本科生进入研究领域的外联活动，包括目前在科学界代表性不足的群体的成员。学生参与德克萨斯大学达拉斯分校的研究预计将为学生才华和创造力的表达和培养提供一个论坛，并提高他们的职业可能性。在这个项目中，Gevorgyan教授的团队正在开发新的温和过渡金属方法来生成以芳基、乙烯基、烷基和杂原子为中心的自由基，以释放它们在现代有机合成中的潜力。正在开发的方法依赖于亲核试剂对亲电中间体的单电子转移(SET)还原。这可以在温和的热或可见光诱导的条件下完成。最初形成的自由基可以经过原子转移(AT)或氢原子转移(HAT)来生成转置的自由基，然后参与进一步的合成转化，包括脂肪族C(Sp3)−H键的官能化、脱饱和或级联环化反应。有利于有效SET、AT和HAT过程的因素正在调查中。如果这些方法得到充分发展，不仅将加深我们对电子转移化学产生活性中间体的理解，还将极大地拓宽合成和药物化学家用于合成和后期修饰复杂分子的工具库。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。

With this award, the Chemical Synthesis Program of the NSF Division of Chemistry is supporting the research of Professor Gevorgyan. His research team is developing novel methods for converting abundant and cheap feedstock materials into value-added products. Carbon-hydrogen bonds plentifully present in organic molecules are targeted for useful elaboration. However, the high strength of the carbon-hydrogen bond prevents its easy breakage and thus may require forcing conditions such as high reaction temperatures, or the use of precious and rare transition metals. Such chemistry may also require the use of highly unstable reagents, which then raise safety concerns. Professor Gevorgyan’s team is investigating very mild and safe transition metal-free methods for generation and manipulation of various reactive species from simple and stable precursors under visible light irradiation. Engagement of this approach allows for mild, efficient, and selective functionalization of organic molecules. The broader impacts of this project include providing new and effective routes into building block molecules of importance in chemical biology and materials science. Moreover, this research has the potential to significantly reduce the cost of chemical reagents needed, and thus have a favorable impact on process efficiency and economy. In addition, Dr. Gevorgyan is actively engaging in outreach activities for recruiting undergraduate students into research, including members of groups that are currently underrepresented in science. Student involvement in research at UT-Dallas is projected to provide a forum for the expression and cultivation of student talent and creativity and enhance their career possibilities.In this project, Professor Gevorgyan’s team is developing new mild transition metal-free methods for generation of aryl-, vinyl-, alkyl- and heteroatom-centered radicals to unlock their potential in modern organic synthesis. The approach under development relies on single electron transfer (SET) reduction of electrophilic intermediates with nucleophilic reagents. This can be accomplished under mildly thermal or visible light-induced conditions. The initially forming radicals may undergo atom transfer (AT) or hydrogen atom transfer (HAT) to generate a transposed radical, which then is involved in further synthetic transformations, including aliphatic C(sp3)−H bond functionalization, desaturation, or cascade cyclization reactions. The factors favoring efficient SET, AT, and HAT processes are under investigation. These methods, if fully developed, would not only deepen our understanding of electron-transfer chemistry for generation of reactive intermediates, but would also substantially broaden the arsenal of tools available for synthetic and medicinal chemists for synthesis and late stage modification of complex molecules.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.