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Development of Novel Selective Reactions Using Neighboring Group Effect of a Sulfenyl Group.

利用硫基的邻近基团效应开发新型选择性反应。

基本信息

批准号：
06453132
负责人：
SAIGO Kazuhiko
金额：
$ 4.74万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

This reserch project is concerned with the development of selective reactions applying the neighboring group effect of a sulfenyl group. First, we tried remote asymmetric induction by the neighboring group participation of a sulfenyl group toward the delta-position. As result, 2-[1-(mesitylthio) alkyl]benzaldehydes and their dimethyl acetals reacted with silylated carbon nucleophiles under Lewis acidic conditions to give the corresponding aldol adducts with high diastereoselectivity, and in some cases, the product was obtained as almost a single diastereomer.Next, the reaction of episulfonium ions generated via neighboring group participation was investigated. Episulfonium ions with an appropriate intramolecular nucleophilic olefin part gave cyclized products, 5-or 6-membered ring carbocycles, with high diastereoselectivity. This reaction is useful for the synthesis of terpenes and steroids.The reaction of glycidyl sulfides, which have a sulfenyl group, participating only at C-2, with trialkylaluminum showed definite C-2 selectivity for uncleophilic ring-opening and gave C-2 alkylated products exclusively with the complete retention of the configuration at the C-2. Upon applying the present reaction, an aggregation pheromone of African Palm Weevil was stereoselectively synthesized in short steps.Amino groups are also known to participate to the neighboring cationic center. Then, similar reactions were carried out with glycidyl amines ; alkylation, alkynylation, and hydride reduction occurred regioselectively at the C-2 position with the retention of the configuration at the C-2.

本研究计画系利用硫基之邻基效应发展选择性反应。首先，我们尝试了通过邻近基团参与的硫基基团向δ-位置的远程不对称诱导。结果表明，在刘易斯酸性条件下，2-[1-（均三甲苯硫基）烷基]苯甲醛及其二甲基缩醛与硅烷基化的碳原子亲核试剂反应，得到了高非对映选择性的羟醛加合物，在某些情况下，产物几乎是单一的非对映异构体。表锍离子与适当的分子内亲核烯烃部分形成环化产物，即5元或6元环碳环，具有高的非对映选择性。该反应可用于合成萜烯和甾体化合物，具有一个仅在C-2位参与的硫代氧乙烯基的缩水甘油基硫醚与三烷基铝的反应显示出一定的C-2亲核开环选择性，并且只得到C-2位烷基化产物，完全保留C-2位构型。应用本反应，在短的步骤中立体选择性地合成了非洲棕榈象甲聚集信息素。氨基也已知参与相邻的阳离子中心。然后，用缩水甘油基胺进行类似的反应;烷基化、炔基化和氢化物还原在C-2位置区域选择性地发生，并保留C-2的构型。