Harnessing the Power of Weak Bonds: Cleavage of N-O Bonds as Key Steps in Domino and Rearrangement Reactions of Functionalized Hydroxylamines

在化学系化学合成(SYN)项目的支持下，莱斯大学的L教授正在研究设计和开发新的简化方法来生产含氮分子。这些新方法为生产中间体和目标分子提供了潜在的更环保、更经济的替代方案，适用于从农业、医药、分子电子到21世纪材料的各种应用。新的分子转变利用了弱的氮-氧(N-O)键，当这些键断裂时，会引发精心安排的化学反应序列，也被称为多米诺骨牌反应。多米诺骨牌过程导致原始分子的骨架重新排列成全新的骨架。这些类型的分子重排反应是化学中已知的最有效和最节省原子的过程之一。库蒂教授一直是莱斯大学化学乐趣分会的教师赞助商，这是一个推广项目，短期目标是在休斯顿地区建立一个强大的卫星项目。长期目标是在德克萨斯州的其他主要大都市区启动类似的卫星项目。这一推广计划为德克萨斯州的K-12学生提供了通过引人入胜的科学实验参与实验学习的机会。通过有趣的演示激起了人们对科学的好奇心，这些演示利用各种榜样突出了重要的教育课。特别是，这个教育项目努力接触到传统上代表人数较少的少数民族，并强调任何人都可以成为科学家！该计划的最终目标是鼓励年轻学生在科学、技术、工程和数学(STEM)领域追求职业生涯。库蒂教授的研究小组将探索四种全新的多米诺骨牌反应策略，以生产小环和芳香族杂环。这些转变的共同主题是底物或中间体的活化性质：通过断裂它们的弱N-O键。根据策略的不同，这种N-O键的断裂要么触发，要么驱动特定的转变，包括新的环收缩和[3，3]-Sigmatrotic重排。合成高取代度含氮分子是合成有机化学中的一个长期挑战。拟议的项目旨在应对这一挑战：裂解N-O键提供的推动力使许多具有挑战性的含氮分子的操作变得简单，包括那些目前化学上未知的分子。这项拟议的研究承诺提供新的、可靠的、无过渡金属的合成方法作为传统方法的替代方法，预计将对学术、政府和工业实验室的化学家产生影响。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 the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Professor László Kürti of Rice University is studying the design and development of new streamlined methods for the production of nitrogen-containing molecules. These new methods offer potentially greener and more economical alternatives for manufacturing intermediates and target molecules for numerous applications ranging from agriculture, medicine, molecular electronics all the way to 21st century materials. The new molecular transformations exploit weak nitrogen-oxygen (N–O) bonds, which when ruptured, initiate carefully orchestrated sequences of chemical reactions, also known as domino reactions. The domino processes cause the skeletons of the original molecules to rearrange into completely new ones. These types of molecular rearrangement reactions are among the most efficient and atom-economical processes known to chemistry. Prof. Kürti has been a faculty sponsor of the Rice University chapter of Fun with Chemistry, an outreach program that has the short-term goal of establishing a robust Houston-area satellite program. The long-term goal is to initiate similar satellite programs in other major Texas metropolitan areas. This outreach program provides K-12 students in Texas with the opportunity to participate in experimental-learning through captivating science experiments. Curiosity for science is piqued through fun demonstrations that highlight important educational lessons by utilizing a variety of role models. In particular, this educational program strives to reach traditionally underrepresented minorities and highlight that anyone can be a scientist! The ultimate goal of the program is to inspire young students to pursue careers in science, technology, engineering, and mathematics (STEM)-fields.Professor Kürti’s research group will be exploring four fundamentally new domino reaction strategies to produce small-ring- and aromatic heterocycles. The common theme of these transformations is the nature of the activation of the substrates or intermediates: by a scission of their weak N–O bonds. Depending on the strategy, this N–O bond cleavage either triggers or drives the particular transformation, which include new ring-contractions and [3,3]-sigmatropic rearrangements. Making highly-substituted nitrogen-containing molecules is a long-standing challenge in synthetic organic chemistry. The proposed project aims to address this challenge: the driving force offered by cleaving N–O bonds enables the operationally simple construction of numerous challenging nitrogen-containing molecules, including ones currently unknown to chemistry. The proposed research promises to offer new, reliable, transition metal-free synthetic methods as alternatives to traditional approaches, and is expected to have impact on chemists in academic, governmental and industrial laboratories.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.