Novel Approaches to Stereo- and Enantioselective Syntheses of Versatile Intermediates via Unsaturated Organometallics of Main Group Metals

该更新补助金由有机合成资助 程序. Zweifel博士正在继续他卓有成效的发展， 含有不饱和度（碳-碳）的有机金属试剂 双键或三键）。 这些试剂有可能 提供了新的路线，在一些不寻常的结构， 信息素在一些害虫和一些化合物使用的海洋 生物体之间相互交流。 研究的具体目标是： (a)乙炔基和烯醇醚基团的制备 将1-甲氧基丁-1-烯-3-炔转化为取代的五元和六元环戊烯， 环内酯，酰基硅烷，1，3-二炔，和 炔-1，2-丙二烯 其特殊之处在于， 转化廉价起始材料的潜力 转化成多种多样的、具有综合吸引力的衍生物; (b)三个潜在亲核中心的开发 1-（三甲基甲硅烷基）-1，3-二炔衍生的单和双（甲锡烷基） 用于合成β-亚烷基-γ-丁内酯的烯炔 和β，γ-不饱和戊内酯。 生物 这些迄今为止还不容易进入的系统的活动 仍有待探索。 钯催化的交叉偶联 甲锡烷基烯炔与亲电试剂的反应将是 研究以获得立体定向的缀合的 烯-二烯、炔-二烯和结构上 特征发生在许多真菌代谢产物中， 抗菌活性; (c)手性3-硼杂环戊烯的制备及表征 它们作为模板进行无环立体防治的用途， 合成中的绝对立体化学的伴随控制 季碳中心和具有三个 连续立体基因中心。

This renewal grant is being funded by the Organic Synthesis Program. Dr. Zweifel is continuing his fruitful development of organometallic regents that contain unsaturation(carbon-carbon double or triple bonds). These reagents have the potential to provide new routes to the unusual structures found in some pheromones in some pests and in some compounds used by sea organisms to communicate with each other. The specific aims of the research are: (a) elaboration of the ethynyl and enol ether groups of 1-methoxybut-1-en-3-yne into substituted five- and six-membered ring lactones, acylsilanes, 1,3-diynes, and yne-1,2-propadienes. The special merit of this lies in its potential for transforming an inexpensive starting material into diverse and synthetically attractive derivatives; (b) exploitation of the three potentially nucleophilic centers of 1-(trimethylsilyl)-1,3-diyne derived mono- and bis(stannyl) enynes for syntheses of beta-alkylidene-gamma-butyrolactones and beta, gamma-unsaturated valerolactones. The biological activities of these hitherto not readily accessible systems remain to be explored. The palladium-catalyzed cross-coupling reactions of stannyl enynes with electrophiles will be investigated to gain access to stereodefined conjugated ene-dienes, yne-dienes, and ene-diynes whose structural features occur in many fungal metabolites, which possess antibiotic activity; (c) preparation of chiral 3-borolenes and investigation of their use as templates for effecting acyclic stereocontrol with concomitant control of absolute stereochemistry in syntheses of quaternary carbon centers and compounds having three consecutive stereogenic centers.