New Syntheses of Highly Reactive and Functional Organometallic Compounds and its Application to Organic Syntheses

在本研究项目中，取得了以下成果。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反应。环化反应是通过羟基的立体定向合成进行的。乙烯基硅烷，(Z)-5-硅基-4-戊烯-1-醇，在亚甲基基醚上带有取代基，顺利地经酸催化环化，分别得到反式-2，5-，顺-2，4-和反式-2，3-二取代四氢呋喃，具有中等到高的立体选择性。含氨基的乙烯基硅烷的酸催化环化反应。吡咯烷的立体选择性合成在酸性催化剂的作用下，含氨基的乙烯基硅烷通过吸电子基团保护，顺利地环化成2-(硅甲基)吡咯烷。这个Cyclzat…2，n-二取代吡咯烷(n=3-5)的立体选择性合成中使用了更多的离子。史无前例的锰介体反应：生成不稳定的羰基叶立德活化的锰以双(氯甲基)醚为前驱体生成不稳定的羰基叶立德，使用该体系以锰为还原剂，叶立德与缺电子的亲偶极分子无需通过还原剂直接还原即可进行反应。三烷基锰(II)酸盐试剂的生成和与亲电试剂的反应，R_3MnLi与碘甲基硫化物反应生成硫甲基锰试剂，其中锰酸盐作为还原剂而不是烷基化试剂。三烷基锰(II)酸盐试剂的还原行为为直接生成一类新的试剂提供了一种协议，具有结构变化的硫甲基锰试剂，生成的硫甲基锰试剂与烯丙基溴化物、烯酮和醛反应。烯丙基锡烷自由基环化反应及以锡烯醇酸盐为自由基转移剂的新自由基反应在AIBN存在下，在β-位带有稳定基团的烯丙基三丁基锡烷与1，6-烯炔反应顺利，以中等至较好的产率得到与锡基和烯丙基结合的环化产物。这种环化反应对于合成高度官能化的五元碳环和杂环是有价值的。与β-氰基烯丙基锡烷反应生成了一定量的双环[4.3.0]非1-烯和单环产物。α-卤代酯、-腈和-酮与锡基烯醇酸盐的自由基引发反应以中等到高产率得到相应的γ-酮衍生物。该均解过程被应用于锡烯醇酸盐、卤代烷和缺电子烯烃之间的三组分偶联反应。用铜(I)盐催化二硅烷在α，β-烯酮中引入硅基的新方法发现，在非质子性极性溶剂中，二硅烷与铜(I)盐的反应能有效地诱导硅-硅键的断裂生成硅基亲核试剂，并发现它与α，β-不饱和烯酮的1，4-加成反应以铜(I)盐的催化量进行。该反应被成功地应用于六甲基二硅烷，生成了迄今为止不易获得的三甲基硅基亲核试剂。较少

The following results are obtained in this research project.1. Silicon-directed Cyclization of Vinylysilanes : Stereoselective Synthesis of Tetrahydrofurans and TetrahydropyransSilicon-directed stereoselective syn addition of hydroxy group to olefinic double bond occurs intramolecularly in an acid-catalyzed cyclization of vinylsilanes bearing hydroxy group. The cyclization proceeds by stereospecific syn addition of the hydroxy group. Vinylsilanes, (Z)-5-silyl-4-penten-1-ols bearing a substituent on the methylene tether, smoothly undergo the acid-catalyzed cyclization to give trans-2,5-, cis-2,4-, and trans-2,3-disubstituted tetrahydrofurans, respectively, with moderate to high stereoselectivity.2. Acid-Catalyzed Cyclization of Vinylsilanes Bearing an Amino Group. Stereoselective Synthesis of PyrrolidinesIn the presence of an acid catalyst, vinylsilanes bearing an amino group protected by an electron-withdrawing group were smoothly cyclized to 2-(silylmethyl) pyrrolidines. This cyclizat … More ion was utilized for the stereoselective synthesis of 2, n-disubstituted pyrrolidines (n=3-5).3. Unprecedented Manganese-Mediated Reactions : Generation of Non-Stabilized Carbonyl YlidsActivated manganese generates nonstabilized carbonyl ylides from bis (chloromethyl) ethers as a precursor, and using this system with manganese as a reductant, the reactions of the ylides with electron-deficient dipolarophiles can be attained without the direct reduction of dipolarophiles by the reductant.4. Manganese Ate Species : Generation and Reactions with ElectrophilesTrialkylmanganese (II) ate reagents, "R_3MnLi" reacted with iodomethylsulfides to produce thiomethylmanganese reagents, where the manganate serves as a reductant not an alkylation agent.The reductive behavior of trialkylmanganese (II) ate reagents provides aprotocol for the direct generation of a new class of reagents, thiomethylmanganese reagents with structural variety, and the generated thiomethylmanganese reagents reacted with allyl bromides, enones and aldehydes.5. Radical Cyclization of 1,6-Enynes Using Allylstannanes and New Radical Reactions Using Stannyl Enolates as Radical Transfer AgentsIn the presence of AIBN, allyltributylstannanes bearing a radical-stabilizing group at the β-position smoothly reacted with 1,6-enynes to give cyclized products incorporated with the stannyl and allyl groups in moderate to good yields. This cyclization is valuable for the synthesis of highly functionalized 5-membered carbocycles and heterocycles. The reactions with β-cyanoallylstannane formed a certain amount of bicyclo [4.3.0] non-1-enes along with monocyclized products. The radical-initiated reactions of α-halo-esters, -nitriles, and -ketones with stannyl enolates gave the corresponding γ-keto derivatives in moderate to high yields. This homolytic process was applied to the three-component coupling reaction among stannyl enolates, haloalkanes, and electron-deficient alkenes.6. New Method for Introduction of a Silyl Group into α, β-Enones Using a Disilane Catalyzed by a Copper (I) salt.The reaction of a disilane with a Cu (I) salt efficiently induces cleavage of the Si-Si bond to generate a silyl nucleophile in an aprotic polar solvent and its 1,4-addition to α, β-unsaturated enones smoothly proceeds with a catalytic amount of a Cu (I) salt were found. This reaction is successfully applied to hexamethyldisilane to generate a trimethylsilyl nucleophile, hitherto not easily accessible. Less