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新的金催化剂。这些催化剂用于加速有机分子的化学反应，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的分子转化为更复杂的分子，然后可以用作药物发现，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，并准备他们作为STEM劳动力的下一代。张博士还参与针对少数民族和高中生的外展工作。此外，张博士正在将金催化纳入本科实验室课程，使他的学生了解他们研究的工业效益。这项工作通过促进工业创新和培训高技术劳动力来促进美国的繁荣。C（sp3）-H键的官能化，特别是未活化的那些，具有很大的合成效用，因为它使得能够在没有底物预官能化的情况下简化合成与药物或材料相关的分子。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。Zhang博士正在研究在亲电溴化试剂存在下，由末端炔酮与金催化剂反应生成的金亚乙烯基的化学。然后这些亚乙烯基络合物插入C-H键中以形成5-或6-元溴代环戊烯酮或溴代环己烯酮。使用其他亲电子试剂，调整的亚乙烯基反应性，并插入到更远程的C-H键也进行了研究，因为这些改变提供了合成的灵活性和访问范围内的有价值的结构。张博士还在研究金催化剂对炔或联烯亲电攻击的活化作用。这些是与具有挑战性的亲核试剂的分子间反应，或与产生有价值的杂环的杂原子亲核试剂的分子内反应。对映体选择性催化，特别是带有手性膦或N-杂环卡宾配体的催化剂，特别适合金（I）络合物的线性结构也很感兴趣。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.