Development of Efficient Homogeneous Gold Catalysis

在化学系化学催化项目的支持下，加州大学圣巴巴拉分校的张黎明博士正在开发从金中提取的新型催化剂。这些催化剂用于加速有机分子上的化学反应，并对形成的产物进行非常精确的控制。这些催化反应将简单分子转化为更复杂的分子，这些分子可以用作药物发现、生物医学研究和材料科学的基石。构建这些目标分子通常是整个合成过程中最困难的部分。所描述的研究是由本科生和研究生进行的，并为他们成为下一代STEM劳动力做好准备。张博士还参与了针对代表性不足的少数民族和高中生的外展工作。此外，张博士正在将黄金催化纳入本科实验课程，以便他的学生了解他们的研究的工业效益。这项工作通过促进工业创新和培训高技术劳动力，促进了美国的繁荣。C(sp3)- h键的功能化，特别是那些未激活的功能化，具有重要的合成用途，因为它可以在没有底物预功能化的情况下简化合成与药物或物质相关的分子。然而，由于反应性和选择性的问题，这种策略的实施具有挑战性，并且仍然不发达。张博士正在研究在亲电溴化试剂的存在下，末端炔酮与金催化剂反应生成的金偏乙烯的化学性质。然后这些偏乙烯配合物插入C-H键，形成5元或6元溴环戊烯酮或溴环己烯酮。研究人员还研究了其他亲电试剂的使用，偏乙烯反应性的调整，以及插入更远的C-H键，因为这些改变提供了合成的灵活性和获得一系列有价值的结构。张博士还研究了金催化剂对炔烃或烯类亲电攻击的活化作用。这些反应要么是具有挑战性的亲核试剂的分子间反应，要么是与杂原子亲核试剂的分子内反应，产生有价值的杂环。对映选择性催化的催化剂携带手性膦或n -杂环羰基配体，专门为金(I)配合物的线性结构量身定做。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Catalysis Program of the Division of Chemistry, Dr. Liming Zhang of the University of California at Santa Barbara is developing new catalysts derived from gold. These catalysts are used to speed up chemical reactions on organic molecules with very precise control of the products formed. These catalysis reactions convert simple molecules to those of greater complexity that can then be used as building blocks in drug discovery, biomedical research, and materials science. The building these target molecules is often the most difficult part of the entire synthetic process. The research described is conducted by undergraduate and graduate students and prepares them as the next generation of the STEM workforce. Dr. Zhang is also involved in outreach efforts targeting underrepresented minorities and high school students. In addition, Dr. Zhang is incorporating gold catalysis into undergraduate laboratory courses, so that his students know of the industrial benefits of their research. This work advances the prosperity of the US by promoting innovation in industry and training of a highly technical workforce. The functionalization of C(sp3)-H bonds, especially those that are unactivated, is of great synthetic utility as it enables the streamlined synthesis of molecules of medicinal- or materials-relevance without substrate pre-functionalization. This strategy, however, is challenging to implement due to issues of reactivity and selectivity, and remains underdeveloped. Dr. Zhang is studying the chemistry of gold vinylidenes generated from the reaction of terminal ynones with gold catalysts in the presence of an electrophilic bromination reagent. These vinylidene complexes then insert into a C-H bond to form a 5- or 6-membered bromocyclopentenone or bromocyclohexenone. The use of other electrophilic reagents, the tuning of the vinylidene reactivity, and the insertion into more remote C-H bonds are also studied as these alterations provide synthetic flexibility and access to a range of valuable structures. Dr. Zhang is also studying the activation of alkynes or allenes towards electrophilic attack by gold catalysts. These are either intermolecular reactions with challenging nucleophiles, or in intramolecular reactions with heteroatom nucleophiles that produce valuable heterocycles. Enantioselective catalysis with catalysts that bear chiral phosphine or N-heterocyclic carbene ligands specifically tailored to the linear structures of gold(I) complexes are also of interest.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.