Studies on Structure and Reactivity of Novel Organometallic Reagents

本课题组拓展了新型功能化有机金属试剂的生成和新合成方法的创新研究。研究的重点是多功能有机金属试剂，主要是双金属试剂的生成，以及利用多金属配合物体系开发新的高选择性反应。在研究项目期间取得的主要研究成果如下：1。宝石双金属试剂的研究：生成与合成应用。提出了利用铅与锌催化的反应，由二卤化物直接制备二锌宝石试剂的可能性。然后，获得了产率较高的宝石双锌试剂。得到的RCH (ZnX)_2 （R=H）、Me、Me_3Si等双金属试剂可用于有机合成；羰基化合物（包括酯）的烯烃化和亲电分步反应。有机镧类试剂的新反应。从非手性二卤化物中发现了更多的α -卤代烷基构建块：sm_2介导的1,1-二碘乙烷与手性醛的反应以高非对映选择性的方式生成手性卤代丙烷。生成手性1-碘乙基反应链。2-溴乙酸乙酯在低温下选择性地得到4-二碘钐-3-氧丁酸乙酯，与酮类和混合酸酐反应，分别得到羟基酮酯和二酮酯。功能有机硅试剂的有机合成。已经公开了几种使用硅环丁烷、二溴甲基硅烷和酰基硅烷的合成反应。研究了各种新的碳-碳形成反应，包括卤代酰基硅烷、酰基硅烷和羰基化合物的三组分偶联。锰在有机合成中的应用。研究了有机锰和锰酸配合物的有机反应；报道了用这些锰进行立体选择性加成不饱和键的有机合成和有机卤化物的还原。少

Investigators of this group extended the research on generation of new functionalized organometallic reagents and innovation on new synthetic methodologies using the reagents. Research was focused on the generation of multifunctional organometallic reagents, mainly dimetallic reagents, and the development of new highly selective reactions using multi-metal complex system. Main research results obtained within the term of the research project are follows.1.Studies on gem-Dimetallic Reagents : Generation and Synthetic Applications.A possibility of direct preparation of gem-dizinc reagents from gem-dihalides was suggested by the use of Pb-catalyzed reaction with Zn. Then, gem-dizinc reagents have been obtained in good yields. Dimetallic reagents thus obtained, RCH (ZnX)_2 where R=H,Me, Me_3Si etc, are useful in organic synthesis ; olefination of carbonyl compounds including ester, and stepwise reaction of electrophiles.2.New Reactions using Organolanthanoid Reagents.Generation of chiral a … More lpha-haloalkyl building block from achiral dihalides has been discovered : SmI_2-mediated reaction of 1,1-diiodoethane with chiral aldehydes gave chiral halohydrin in high diastereoselective manner. Chiral 1-iodoethyl reactive block was generated. Ethyl 2-bromoacetate gives ethyl 4-diiodosamario-3-oxo-butanoate selectively in low temperature, whose reaction with ketones and mixed anhydrides afforded hydroxy keto esters and diketo esters, respectively.3.Organic Synthesis Using Functional Organosilicon Reagents.Several synthetic reactions using silacyclobutane, dibromomethylsilanes, and acylsilanes have been disclosed. Various new carbon-carbon forming reactions have been studied, including threecomponent coupling of haloacylsilanes, acylsilane, and carbonyl compounds.4.Use of Manganese in Organic Synthesis.Some organic reactions using organomanganese and manganese ate-complexes have been studied ; organic synthesis using these manganese species in stereoselective addition to unsaturated bonds and reduction of organic halides were reported. Less