Pincer-ligated catalysts for borylation of alkynes

化学催化计划支持德克萨斯农工大学主校区的奥列格·V·奥泽罗夫教授的努力，以探索研究人员实验室最近发现的一种新反应的潜力：末端炔烃的脱氢硼化反应(DHBTA)。DHBTA由精选的Ir钳形络合物催化，在温和的条件下直接将末端炔烃转化为炔基硼酸酯，具有良好的选择性。炔基硼酸酯在有机化学中是非常有吸引力的构件，在偶合反应中可用作炔基的来源，在各种加成反应和环加成反应中可用作炔基。后一系列反应导致新化合物的形成，否则很难获得碳-硼键，这些碳-硼键可用于进一步精制成更复杂的分子。这项研究包括设计新的钳形配体及其金属络合物，探索DHBTA的机理和范围，并展示了炔基硼酸酯在炔-炔偶联成烯炔以及在Pauson-Khandd合成硼化环戊酮中的应用。奥泽罗夫教授和他的研究团队通过与主要是本科院校和美国以外的研究人员合作，通过让本科生参与德克萨斯农工大学的研究，以及通过接触当地高中，扩大了他们研究活动的影响。在化工和制药行业中，高价值有机化学品的分子组装往往依赖于过渡金属化合物的催化作用。这项研究代表了一种新的方法来使用定义明确的分子过渡金属络合物来催化形成具有碳-硼键的化合物。含碳-硼键的有机化合物在合成复杂有机结构中具有极其广泛的用途。这个项目提供了关于分子水平上成功的过渡金属催化剂设计和操作的新的基础知识，探索了新的可获得的构建块在合成中的精选用途，并为各种不同的学生提供了关于过渡金属最先进的化学以及最重要的是批判性思维和解决科学问题的艺术的培训。

The Chemical Catalysis Program supports the efforts of Professor Oleg V. Ozerov of Texas A&M University Main Campus to explore the potential of a new reaction recently discovered in the investigator's laboratory: dehydrogenative borylation of terminal alkynes (DHBTA). DHBTA is catalyzed by select iridium pincer complexes and converts terminal alkynes directly into alkynylboronates under mild conditions and with excellent selectivity. Alkynylboronates are very attractive building blocks in organic chemistry that can be used as either sources of the alkynyl group in coupling reactions or as alkynes in various addition and cycloaddition reactions. The latter set of reactions leads to the formation of new compounds with otherwise difficult to access carbon-boron bonds that can be used for further elaboration into more complex molecules. This research combines efforts in the design of new pincer ligands and their metal complexes, exploration of the mechanism and scope of DHBTA, and demonstration of the utility of alkynylboronates in alkyne-alkyne coupling to enynes and in Pauson-Khand synthesis of borylated cyclopentenones. Prof. Ozerov and his research group broaden the impact of their research activities via collaborations with researchers at primarily undergraduate institutions and outside of the US, through involvement of undergraduate students in research at Texas A&M, as well as through outreach to local high schools. The molecular assembly of high-value organic chemicals in the chemical and pharmaceutical industries often relies on catalysis by transition metal compounds. This research represents a new approach to using well-defined, molecular transition metal complexes to catalyze the formation of compounds with carbon-boron bonds. Organic compounds containing carbon-boron bonds are extremely versatile as building blocks in the synthesis of complex organic structures. This project provides new fundamental knowledge about the design and operation of successful transition metal catalysts on the molecular level, explores select uses of the newly accessible building blocks in synthesis, and provides training to a diverse array of students in state-of-the-art chemistry of transition metals and, most importantly, in the art of critical thinking and solving scientific problems.