New Generation of Reactive 1,3-Dipole and Radical Reagents and Dynamic Sterocontrol

1.乙烯基硅烷的硅导向环化反应：四氢呋喃和四氢吡喃的立体选择性合成在酸催化下，羟基与烯属双键的硅导向立体选择性合成反应发生在分子内。环化通过羟基的立体定向合成加成进行。乙烯基硅烷（Z）-5-甲硅烷基-4-戊烯-1-醇的亚甲基链上带有取代基，可以顺利地进行酸催化环化反应，分别得到反式-2，5-、顺式-2，4-和反式-2，3-二取代四氢呋喃，具有中等至高的立体选择性.带有氨基的乙烯基硅烷的酸催化环化。吡咯烷的立体选择性合成在酸性催化剂存在下，带有吸电子基团保护的氨基的乙烯基硅烷顺利地环化为2-（硅甲基）吡咯烷。该环化反应被用于2，n-二氮杂双环戊二烯的立体选择性合成。 ...更多信息 取代的吡咯烷（n=3-5）。前所未有的锰介导的反应：不稳定羰基叶立德的产生活性锰以双（氯甲基）醚为前体生成不稳定羰基叶立德，并使用该体系以锰为还原剂，可以实现叶立德与缺电子亲偶极试剂的反应，而不需要还原剂直接还原亲偶极试剂.锰食源性物种：三烷基锰（II）酸盐试剂R_3MnLi与碘甲基硫醚反应生成硫甲基锰试剂，其中三烷基锰（II）酸盐试剂R_3MnLi起还原剂而非烷基化剂的作用。三烷基锰试剂的还原行为为直接生成一类新的试剂--结构多样的硫代甲基锰试剂以及生成的硫代甲基锰试剂与烯丙基溴、烯酮和β-环糊精的反应提供了一种途径.使用烯丙基锡烷的1，6-烯炔的自由基环化反应和使用锡烯醇化物作为自由基转移剂的新自由基反应6.用铜（I）盐催化的乙硅烷将甲硅烷基引入α，β-烯酮的新方法。乙硅烷与铜（I）盐的反应有效地诱导Si-Si键的断裂以在非质子极性溶剂中生成甲硅烷基亲核试剂，发现β-不饱和烯酮在催化量的Cu（I）盐作用下可以顺利进行，该反应成功地应用于六甲基二硅烷生成三甲基硅基亲核试剂，到目前为止不容易获得。首次对过渡金属α-氰基碳负离子的C-和N-键合异构体的结构和反应性进行了系统的研究。从结构分析、有机金属转化和机理研究的角度，已经阐明了配体的立体化学对它们的反应性和催化作用的巨大贡献8。在五羰基钨催化的ω-炔硅烯醇醚环化反应中，通过选择合适的反应条件，实现了反应途径的动态控制，选择性地得到外环或内环化产物。少

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 cyclization was utilized for the stereoselective synthesis of 2,n-dis … More ubstituted 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 a protocol 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 Agents6. 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.7. The first systematic studies on the structure and reactivities of C-and N-bound isomers of transition metal a-cyanocarbanions have been carried out. Strong contribution of stereochemistry of ligands to their reactivities and catalysis has been clarified in view of structural analysis, organometallic transformations, and mechanistic investigations8. Dynamic control of the reaction pathways in the pentacarbonyltungsten catalyzed cyclization of ω-acetylenic silyl enol ethers is achieved giving either exo or endo cyclized product selectively by the appropriate choice of the reaction conditions. Less