Pincer-ligated catalysts for borylation of alkynes

化学催化项目支持德克萨斯a&m大学主校区的Oleg V. Ozerov教授的努力，以探索最近在研究者实验室发现的一种新反应的潜力：末端炔的脱氢硼化（DHBTA）。DHBTA在选择性铱螯合物的催化下，在温和的条件下，以优异的选择性将末端炔直接转化为硼炔酸酯。炔基硼酸盐是有机化学中非常有吸引力的组成部分，既可以作为偶联反应中炔基的来源，也可以作为各种加成和环加成反应中的炔基。后一组反应导致新化合物的形成，否则难以获得碳硼键，可用于进一步细化成更复杂的分子。本研究结合了新的钳形配体及其金属配合物的设计，DHBTA的机制和范围的探索，以及炔基硼酸盐在炔-炔偶联炔和硼化环戊酮的Pauson-Khand合成中的应用。Ozerov教授和他的研究小组通过与主要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，以及通过与当地高中的联系，扩大了他们研究活动的影响。在化学和制药工业中，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使用定义明确的分子过渡金属配合物催化碳硼键化合物形成的新方法。含有碳硼键的有机化合物在复杂有机结构的合成中是非常通用的。该项目提供了在分子水平上成功设计和操作过渡金属催化剂的新基础知识，探索了合成中新可获得的构建块的选择用途，并为各种各样的学生提供了过渡金属最先进化学的培训，最重要的是，在批判性思维和解决科学问题的艺术方面。

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.