RUI: Phosphorus-Directed C-H Borylation and Reactivity of Phosphaboronates

在化学系化学催化计划的支持下，圣地亚哥大学的蒂莫西·克拉克教授正在研究过渡金属催化的过程，这种过程能够将硼选择性地引入到含有磷的有机分子中。还在调查允许用其他最终感兴趣的组取代硼残留物的后续反应，目的是实现增值有机磷产品的制造。这些努力意义重大，因为预计将在硼化和硼转化化学方面取得根本性进展，并由于正在产生的各种有机磷产品的重要性，这些产品具有作为药剂、农用化学品和其他具有广泛用途的先进材料的潜在应用。克拉克教授主要与圣地亚哥大学的本科生同事一起工作，因此，该资助项目的更广泛影响将延伸到STEM(科学、技术、工程和数学)领域的年轻人的教育和培训。此外，参与该项目的一名博士后助理将得到PI的指导，为未来的研究和教学事业奠定基础，从而进一步丰富科学和教育领域的人力资源库。受资助的研究集中在显著扩展C-H硼化化学的最新进展，以实现有效的新路线，以获得有价值的手性膦和膦酸盐。目前正在追求两个不同的目标，以烷基或芳基有机磷化合物为背景探讨这一主题。在目标1中，正在研究在手性配体存在下，Ir催化的C(SP3)-H硼化烷基膦、磷酸盐和相关的有机磷物种，以实现仲烷基硼酸酯的对映选择性合成。将这种化学与允许C-B键立体定向转化为C-C或C-X(X=O，N)键的反应范围进行排序，可以方便地合成有用的富对映体手性膦。在目标2中，正在通过新的氧化铜催化的同位和异位偶联过程来探索由芳基磷酸盐在磷指导的邻位硼化反应中生成联芳基的反应。以对映体选择性的方式执行这一化学的机会也在调查中，该化学提供了一条通往某些重要类别的轴向手性双膦配体的简明路线。这一奖项反映了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 Catalysis Program in the Division of Chemistry, Professor Timothy Clark of the University of San Diego is studying transition metal-catalyzed processes that enable the selective introduction of boron into organic molecules that contain phosphorus. Subsequent reactions that allow for replacement of the boron residue with yet other groups of ultimate interest are also under investigation with the net aim of achieving the manufacture of value-added organophosphorus products. These endeavors are significant because of the fundamental advances to borylation and boron-conversion chemistry that are anticipated and due to the importance of the kinds of organophosphorus products being generated, which have potential applications as pharmaceutical agents, agrochemicals, and other advanced materials of broad utility. Professor Clark works primarily with undergraduate student coworkers at the University of San Diego and, accordingly, the broader impacts of the funded project will extend to the education and training of young people in STEM (science, technology, engineering and mathematics) fields. In addition, a post-doctoral associate working on the project will receive mentoring from the PI to build toward a future career in research and teaching thus further enriching the pool of human resources in science and education.The funded research is focused on significantly expanding recent advances in C–H borylation chemistry to enable efficient new routes to valuable chiral phosphines and phosphonates. Two distinct aims are being pursued that explore this theme in the context of either alkyl or aryl organophosphorus compounds. In Aim 1, iridium-catalyzed C(sp3)–H borylation of alkyl phosphines, phosphonates, and related organophosphorus species, is being investigated in the presence of chiral ligands to achieve an enantioselective synthesis of secondary alkyl boronates. Sequencing this chemistry with the expansive range of reactions that allow for the stereospecific conversion of C–B bonds into C–C or C–X (X = O, N) bonds allows for expedient syntheses of useful enantioenriched chiral phosphines. In Aim 2, biaryl formation from aryl boronates generated by phosphorus-directed ortho borylation of aryl phosphonates, is being explored via novel oxidative copper-catalyzed homo- and hetero-coupling processes. Opportunities for executing this chemistry, which offers a concise route to some important classes of axially chiral bisphosphine ligands, in an enantioselective modality are also under investigation.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.