CATALYTIC C-C BOND FORMING REACTIONS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。过渡金属催化的烯烃和炔烃的偶联反应是形成共轭化合物的有效方法，在工业过程和天然产物合成中具有广泛的应用。本课题组目前的研究目标之一是研究烯烃和炔烃的催化碳-碳键形成反应的基本方面。特别是，我们采用定义明确的正离子-乙炔化物和-亚烷基配合物作为催化剂，研究了几个新的烯烃和炔烃的催化偶联反应的详细机制。我们发现原位生成的炔鎓-乙炔配合物1是一种有效的炔交叉二聚催化剂。我们还发现，金属环戊二烯2是一个高选择性的催化剂，乙炔和烯烃的线性偶联反应，以产生庚三烯产品。结果表明，新合成的阳离子季铵盐-亚烷基配合物3是一种优良的炔烯氢加成催化剂。我们目前正在研究详细的反应机理，并正在寻找新一代的金属催化剂用于烯烃和炔烃的偶联反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Transition metal-catalyzed coupling reactions of alkenes and alkynes are effective methods of forming conjugated compounds that have wide range of applications in industrial processes and natural product syntheses. One of our group's current research goals is to study the fundamental aspects of catalytic carbon-carbon bond forming reactions of alkenes and alkynes. In particular, we employ well-defined ruthenium-acetylide and -alkylidene complexes as catalysts to study the detailed mechanisms for several new catalytic coupling reactions of alkenes and alkynes. We found that the in-situ formed ruthenium-acetylide complex 1 is an effective catalyst for the cross dimerization of alkynes. We also discovered that the metallacyclopentadiene 2 is a highly selective catalyst for the linear coupling reaction of acetylene and alkenes to yield heptatriene products. The newly synthesized cationic ruthenium-alkylidene complex 3 was found to be excellent catalyst for the hydrovinylation of alkynes. We are currently investigating the detailed reaction mechanisms, and are searching for the next generation of metal catalysts for coupling reactions of alkenes and alkynes.