Novel Catalytic Transformations of Organoboron Species and the Development of Ultrastable Self-Assembled Monolayers on Metal Surfaces

有机硼物质的新型催化转化和金属表面超稳定自组装单分子层的开发

• 批准号: RGPIN-2016-04667
• 负责人: Crudden, Cathleen
• 金额: $ 9.18万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709424
• 关键词: Novel; Catalytic; Transformations; Organoboron; Species

The proposed research is based on two exciting discoveries from our lab. In 2014, we demonstrated that NHCs form monolayers on gold that withstand unprecedented extremes of heat, oxidant, acid and base. This work was called "game changing" by international experts, including Häkkinen, director of the Nanoscience Centre in Finland. Other experts called it "the new gold standard" and "elegant". NHCs have been known to form strong bonds in transition metal complexes but had not previously been examined as alternatives to thiols for self-assembled monolayers on metals. In this proposal, we will explore many aspects of this novel and exciting discovery, including: (1) the effect of NHC structure on film quality and bond strength, (2) the use of NHCs to form films on other metals including Ag and Cu where the NHC coating may help prevent oxidation and tarnishing, and (3) the use of NHCs in magic number Au clusters, which are remarkable molecular materials, that have been largely prepared with thiol ligands and thus NHCs will provide a completely new type of nanomaterial. In long term goals, we will (4) explore the use of NHCs in molecular electronics and as modifiers for catalytically active surfaces and nanoparticles. Many collaborations for this project are already in place, including with Horton (surface science, Queen's), McLean (STM imaging, Queen's Physics), Baddeley (STM imaging, St. Andrews), Kraatz (Electrochemistry, U of T Scar.), Häkkinen (Theory, Finland), Mosey (Theory, Queen's) and Tsukuda (nanoclusters, Japan). The second part of this proposal builds on recent discoveries in catalysis, where we demonstrated that organic molecules with practically identical boron substituents can undergo selective, orthogonal coupling by manipulating the ability of the CB bond to transmetalate to Pd. This back-to-back Suzuki coupling without protecting groups had never been accomplished prior to our Nature Comm. paper (in revision). In this grant, we will study the control elements in the stereochemistry of the transmetalation reaction. We will employ more complex coupling partners containing both a nucleophile and an electrophile, and will study deborylation as a completely novel method for the preparation of chiral boron compounds as critical starting materials for this transformation. Aspects of this project will be collaborative with Chirik (Princeton). Student salaries are 70% of the proposed budget, representing my significant commitment to training. The proposed chemistry is even more multidisciplinary than previous projects and thus funds are allocated for collaborative visits. I plan to continue to provide all PhD students the opportunity to carry out research abroad during their degree. This has been highly successful for broadening the experience of my HQP, forming international networks and making contacts for future job/PDF positions.

拟议的研究基于我们实验室的两项令人兴奋的发现，我们证明 NHC 在金上形成单分子层，可以承受前所未有的极端高温、氧化剂、酸和碱，这项工作被包括在内的国际专家称为“改变游戏规则”。芬兰纳米科学中心主任 Häkkinen 称其为“新的黄金标准”和“优雅的”，众所周知 NHC 可以在过渡金属配合物中形成牢固的键，但之前并未经过研究。作为金属上自组装单分子层的硫醇的替代品在本提案中，我们将探讨这一新颖且令人兴奋的发现的许多方面，包括：（1）NHC 结构对薄膜质量和粘合强度的影响，（2）用途。 NHC 在包括银和铜在内的其他金属上形成薄膜，其中 NHC 涂层可能有助于防止氧化和变色，以及（3）在幻数金簇中使用 NHC，这是一种非凡的分子材料，已在很大程度上由硫醇配体制备，因此 NHC 将提供一种全新类型的纳米材料。从长远目标来看，我们将 (4) 探索 NHC 在分子电子学中的应用以及作为催化活性表面和纳米粒子的改性剂。已经就位，包括 Horton（表面科学，女王大学）、McLean（STM 成像，女王大学物理）、Baddeley（STM 成像，圣安德鲁斯）、Kraatz （电化学，多伦多大学斯卡分校）、Häkkinen（理论，芬兰）、Mosey（理论，女王大学）和 Tsukuda（纳米团簇，日本）。 该提案的第二部分建立在催化领域的最新发现的基础上，我们证明了具有几乎相同的硼取代基的有机分子可以通过操纵 CB 键金属转移为 Pd 的能力来进行选择性的正交偶联。在我们的《自然通讯》论文（修订版）之前，我们将研究金属转移反应的立体化学中的控制元素。包含亲核试剂和亲电试剂的更复杂的偶联伙伴，并将研究脱硼作为一种制备手性硼化合物的全新方法，作为该转化的关键起始材料。该项目的各个方面将与 Chirik（普林斯顿大学）合作。 学生工资占拟议预算的 70%，这代表了我对培训的重大承诺，所提议的化学比以前的项目更加跨学科，因此我计划继续为所有博士生提供开展合作访问的机会。在攻读学位期间进行海外研究，这对于扩大我的 HQP 经验、形成国际网络以及为未来的工作/PDF 职位建立联系非常成功。