A New Approach to the Construction of Carbon Framework Using Metallacumulene Derivatives

1,2 -丙烯（烯）作为独特的合成试剂，具有累积的双键基团，有许多反应。其中有效地利用了累积双键的特点，这是简单的双键或三键所不能达到的。在本研究中，我将偏二烯和烯二烯配合物分别视为1,2 -丙二烯和1,2,3 -丁烯的金属类似物，并关注了金属聚酰亚胺中碳-碳双键的反应性。我计划寻找能充分利用其特性的合成反应，并使用金属累积烯作为两个或三个碳单元。我首先研究了从铑和铱中合成偏乙烯络合物的方法，这两种金属都是富含电子的金属。根据传统的方法，我尝试从低价铑配合物和末端炔通过异构化和氢转移制备它们。通过炔基环加成得到了多环化合物。因此，我致力于开发低价晚期过渡金属催化的烷烃和烯烃的环加成反应，特别是使用手性金属催化剂的对映选择反应。例如，过渡金属催化的[2+2+2]环加成反应是构建六元环体系的一种行之有效的方法。开发了一种新型的对映选择性[2+2+2]环加成法合成季碳立体中心。各种1,4 -二烯炔在手性铑催化剂下进行分子内反应，根据1,4 -二烯部分取代基的不同，得到了具有张力双环[2.2.1]庚烯骨架或双环- 1,3 -二烯的三环化合物。

There are many reactions of 1, 2-propadienes(allenes), which have cumulated double bond moieties, as unique synthetic reagents. Among them, the features of the cumulated double bond are effectively utilized, that cannot be achieved by simple double or triple bond. In this research, I recognize vinylidene and allenylidene complexes as metal analogue of 1, 2-propadienes and 1, 2, 3-butatriene, respectively, and pay attention to the reactivity of carbon-carbon double bond in metallacumulenes. I plan to search for synthetic reactions that make the best use of their characteristics, and that use metallacumulenes as two or three carbon unit.I first examined the synthesis of vinylidene complexes from rhodium and iridium ones, which are known to be relatively electron-rich metals. According to the conventional methods, I tried to prepare them from low valent rhodium complexes and terminal alkynes via isomerization along with a hydrogen transfer. I failed but obtained multicyclic compounds by cycloaddition of alkyne moieties. Thus, I focused on the development of low valent late transition metal catalyzed-cycloaddition of alkynes and alkenes, especially enantioselective reaction using chiral metal catalysts.For example, transition metal-catalyzed[2+2+2] cycloaddition is a well-established protocol for the construction of six-membered ring systems. I developed a new type of enantioselective[2+2+2] cycloaddition for the synthesis of quaternary carbon stereocenters. The intramolecular reaction of various 1, 4-diene-ynes proceeded using a chiral rhodium catalyst and tricyclic compounds possessing a strained bicyclo[2.2.1] heptene skeleton or bicyclic cyclo-1, 3-dienes were obtained, depending on the substituent on the 1, 4-diene moiety.