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CHEMOSELECTION CONTROL OF DIELSALDER REACTIONS USING TWO CONJUGATE DIENES

使用两种共轭二烯对迪尔萨尔德反应进行化学选择控制

基本信息

批准号：
13555248
负责人：
KANEMASA Shuji
金额：
$ 8.83万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

Establishment of a synthetic method for chemoselectivity control in Diels-Alder reactions using two kinds of conjugate dienes, both of which can act as dienes and dienophiles depending upon the reaction conditions. Two possible combinations are possible for the chemoselectivity, and other selectivities such as regio- and diastereoselectivities. We have investigated the reactions using two different conjugate dienes, such as acyclic and cyclic ones, in the presence of a variety of catalysts.2-Methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and cyclopentadiene have been selected as conjugate 1,3-dienes; nucleophiles such as the same 1,3-dienes and nitrones as 1,3-dipole have been used.. For the Diels-Alder reactions using these conjugate dienes and nitrone dipolar cycloadditions toward these conjugate dienes, a variety of Lewis acid catalysts such as halogens themselves, halonium ions having noncordinating halonium ions, N-haloammonium and N-halopyridinium salts have been applied in catalytic amounts. However, these catalysts are all ineffective for the activation.Silyl cations, sulfonium cations, and selenium cations, which have been generated in situ by interaction of the corresponding halide derivatives with silver borontetrafluoride, have failed to accelerated the reactions. Allylic cation species have been generated from allylic acetates and carbonates in the presence of palladium zero catalysts and allowed to react with conjugate dienes and nitrones. However, no specific effect has not been observed.

利用两种共轭二烯建立了控制Diels-Alder反应化学选择性的合成方法，这两种共轭二烯都可以作为二烯和亲二烯体，这取决于反应条件。两种可能的组合对于化学选择性和其他选择性如区域选择性和非对映选择性是可能的。我们研究了在不同催化剂存在下，两种不同共轭二烯（如无环和环状共轭二烯）的反应，选择了2-甲基-1，3-丁二烯、2，3-二甲基-1，3-丁二烯和环戊二烯作为共轭1，3-二烯，使用了亲核试剂如1，3-二烯和硝酮作为1，3-偶极试剂。对于使用这些共轭二烯和硝酮对这些共轭二烯的偶极环加成的狄尔斯-阿尔德反应，已经以催化量应用了各种刘易斯酸催化剂，例如卤素本身、具有非配位卤离子的卤离子、N-卤铵和N-卤代吡啶盐。然而，这些催化剂对活化都是无效的，通过相应的卤化物衍生物与四氟化银相互作用原位产生的甲硅烷基阳离子、锍阳离子和硒阳离子未能加速反应。烯丙基乙酸酯和碳酸酯在钯零催化剂存在下生成烯丙基阳离子物种，并使其与共轭二烯和硝酮反应。然而，尚未观察到任何特定效果。