New Reactions Using Highly Functional Organometallic Compounds and its Application to Synthetic Chemistry

1.硅导向的乙烯基硅烷环化反应：四氢呋喃和四氢吡喃的立体选择合成硅导向的立体选择性合成在含羟基的乙烯基硅烷的酸催化环化反应中，分子内发生羟基与烯烃双键的立体选择性合成。因此，5-二甲基苯基硅基-4-戊烯-1-醇在催化量的对甲苯磺酸(TsOH)或TiCl4.2的作用下顺利环化为2-(二甲基苯基硅基)甲基四氢呋喃。在我们研究活性物种的生成和反应的过程中，我们报告了He…更多地抑制了由钐介导的碘甲基硅基醚生成新的活性物种，非稳定的羰基叶立德，以及它们的[3+2]环加成反应到各种不饱和化合物，如醛，烯，烯和炔。3.锰物种：生成和与亲电试剂反应四丁基锰酸盐络合物‘Bu_4MnLi_2’与烯丙基和丙基-2-芳基溴化物反应生成相应的烯丙基和丙基-2-炔基锰物种，这些物种进一步与亲电极如醛、酮、环氧化物、环氧化物反应4.烯丙基锡化反应：二取代和三取代乙烯基锡烷的立体选择性合成在AIBN存在下，在β-位带有吸电子基团的烯丙基锡烷很容易与末端和缺电子的内部炔烃反应，以中等到较好的产率得到β-烯丙基取代的乙烯基锡烷。烯丙基锡化反应排他地以反加成进行。烯丙基锡烷在β-位带有一个吸电子基团，很容易与各种缺电子的烯烃反应，引入烯丙基和锡基。较少

The following results are obtained in this research project.1.Silicon-directed Cyclization of Vinylysilanes : Stereoselective Synthesis of Tetrahydrofuranes and TetrahydropyranesSilicon-directed stereoselective syn addition of hydroxy group to olefinic double bond occurs intramolecularly in an acid-catalyzed cyclization of vinylsilanes bearing hydroxy group. Thus 5-dimethylphenylsilyl-4-penten-1-ol is smoothly cyclized to 2- (dimethylphenylsilyl) methyltetrahydrofuran upon the treatment of a catalytic amount of p-toluenesulfonic acid (TsOH) or TiCl_4.2.Unprecedented Samarium-Mediated Reactions : Generation of Non-Stabilized Carbonyl YlidsSamarium reveals a strong reducing ability and by virtue of this character together with its oxophilicity, is widely applied to organic synthesis in the formation of carbon-carbon bonds and transformation of a variety of functionalities with high selectivities. In the course of our study on the generation and reactions of reactive species, we report he … More rein the generation of novel active species, non-stabilized carbonyl ylids from iodomethyl silyl ethers mediated by samarium, otherwise inaccessible, and their [3+2] cycloadditions to a variety of unsaturated compounds such as aldehydes, alkenes, allenes, and alkynes.3.Manganese AteSpecies : Generation and Reactions with ElectrophilesTetrabutylmanganese ate complex 'Bu_4MnLi_2' reacts with allylic and prop-2-ynylic bromides to generate the corresponding allyl-and prop-2-ynyl-manganese species which further react with electrophiles such as aldehydes, ketones, epoxide, and chlorosilanes to afford the corresponding allylated and prop-2-ynylated and/or allenylated products in high yields.4.Allylstannylation of Alkynes and Alkenes via a Radical Process : Stereoselective Synthesis of Di-and Tri-Substituted VinylstannanesIn the presence of AIBN,allylstannanes bearing an electron-withdrawing group at the beta-position easily reacted with terminal and electron-deficient internal alkynes to give beta-allyl-substituted vinylstannanes in moderate to good yields. The allylstannylation proceeds with anti addition exclusively. Allylstannanes bearing an electron-withdrawing group at the beta-position easily reacted with various electron-deficient alkenes to introduce both the allyl and stannyl groups. Less