Molecular Design for Creation of Synthetic Equivalents and Reseach Development for the Application to Organic Synthesis

1.新的二异亚甲基化合物和稠合异恶唑的合成我们制备并使用了(三甲基硅甲基)乙烯羧酸甲酯作为亲偶极试剂和一种常见的关键化合物，用于合成二异亚甲基化合物的前驱体，然后与烯烃以[4+2]环加成的方式反应得到稠杂环化合物。2.通过3-甲硫基-4-三甲基硅基-1，2-丁二烯与烯烃在Lewis酸作用下的[2+2]环加成反应，再与烯烃进行[2+2]环加成反应，再经氧化和1，2-消除反应合成二异亚甲基环丁烷。通过[4+3]与2-氧基烯丙基阳离子的环加成反应，还成功地将二异亚甲基环丁烷用于构建了双环[5.2.0]正庚烷环合体系。标题化合物可正式视为1，2，3-丁三烯或1，3-丁二烯-2，3-二基的合成等价物。3.羰基叶立德和相关的1，3-偶极试剂的生成和反应1，3-偶极试剂从合成和理论上都是重要而有趣的化学物种。我们发现，在温和的中性条件下，通过α-芳基取代的氯甲基三甲基硅基甲醚的硅基1，3-消除反应可以方便地生成简单的羰基叶立德，否则这些化合物是无法获得的，这使得二氢呋喃和四氢呋喃以及相关的杂芳烃可以通过[3+2]环加成到包括C=C，C*C，C=O，C=S，C=N，N=N在内的多种pi键上一步合成。

1.Synthesis of new di-exo-methylene compounds and fused isoxazolesWe have prepared and used methyl (trimethylsilylmethyl) acetylenecarboxylate as a dipolarophile and a common key compound leading to precursors for di-exo-methylene compounds which subsequently react with olefins in [4+2] cycloaddition mode to afford fused heterocyclic compounds. We found a new and general route toward the synthesis of the precursor for di-exo-methyleneisoxazolines and their Diels-Alder reactions leading to fused isoxazoles.2.New access to di-exo-methylenecyclobutanes via [2+2] cycloaddition of 3-methylthio-4-trimethylsilyl-1,2-butadiene with alkenes mediated by a Lewis acidIn the course of studies in organic synthesis using allylsilanes and propargylsilanes, we found a new and general route toward the synthesis of di-exo methylenecyclobutanes via the [2+2] cycloaddition of 3-methylthio-4-trimethylsilyl-1,2-butadiene with alkenes promoted by a Lewis acid followed by sequential reactions to sulfones by oxidation and 1,2-elimination. Di-exo-methylenecyclobutanes were also successfully applied to construct a bicyclo [5.2.0] nonane ring system by the [4+3] cycloaddition with an 2-oxyallyl cation. The title compound can be viewed formally as a synthetic equivalent of 1,2,3-butatriene or 1,3-butadien-2,3-diyl.3.Creation and Reactions of Carbonyl Ylides and Related 1,3-Dipolar Reagents1,3-Dipolar reagents are important and interesting chemical species from both synthetic and theoretical points of view. We found that the novel findings that simple carbonyl ylides, otherwise inaccessible, were indeed expediently generated by the silicon-based 1,3-elimination from alpha-aryl-substituted chloromethyl trimethylsilylmethyl ether under mild and neutral conditions which provided the powerful one-step synthesis of dihydrofurans and tetrahydrofurans and related heterocylesvia[3+2]cycloadditions to a vareity of multiple pi-bonds including C=C,C*C,C=O,C=S,C=N,N=N.