Highly enantioselective Diels-Alder reactions of 1-amino-3-siloxy-dienes catalyzed by Cr(III)-salen complexes
Highly enantioselective Diels-Alder reactions of 1-amino-3-siloxy-dienes catalyzed by Cr(III)-salen complexes
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DOI：
10.1021/ja002058j
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发表时间：
2000-08-16
影响因子：
15
通讯作者：
Rawal, VH
中科院分区：
文献类型：
--
作者：
Huang, Y;Iwama, T;Rawal, VH
Diels-Alder（DA）反应可能是立体控制合成复杂分子的最有效的方法。1在一个步骤中，它产生具有一个至多达四个立体中心的六元碳环和杂环。在该反应的许多进展中，2-4特别重要的是许多手性刘易斯酸催化的环加成。5，6报道的成功的对映选择性DA反应的大部分涉及使用环二烯，最常见的是环戊二烯。5 b在所报告的无环二烯中，大多数是单取代丁二烯。7令人惊讶的是，多个杂原子取代的二烯，如Danishefsky的二烯，8的对映选择性DA反应似乎还没有报道，尽管它们在复杂分子合成中有巨大的用途。[9]结合我们对1-氨基-3-甲硅烷氧基-1，3-丁二烯化学的兴趣，[10]我们研究了手性刘易斯酸催化的这些二烯的环加成反应。本文报道了1-氨基-3-甲硅烷氧基-1，3-丁二烯与各种丙烯醛在铬（III）-salen催化剂作用下的反应，以极高的对映选择性得到了高度官能化的环己烯衍生物。
The Diels-Alder (DA) reaction is perhaps the most powerful method for the stereocontrolled synthesis of complex molecules. 1 In a single step it produces six-membered carbocycles and heterocycles with from one to as many as four stereocenters. Among the many advances with this reaction, 2-4 of particular significance are the numerous chiral Lewis acid-catalyzed cycloadditions. 5, 6 A large percentage of successful enantioselective DA reactions reported involve the use of a cyclic diene, most commonly cyclopentadiene. 5b Of the acyclic dienes reported, most are monosubstituted butadienes. 7 Surprisingly, enantioselective DA reactions of multiply heteroatom-substituted dienes, such as Danishefsky’s diene, 8 appear to not have been reported despite their tremendous usefulness in complex molecule synthesis. 9 In connection with our interest in the chemistry of 1-amino-3-siloxy-1, 3-butadienes, 10 we have explored the chiral Lewis acid catalyzed cycloadditions of these dienes. We report here that the reactions of 1-amino-3-siloxy-1, 3-butadienes with various acroleins catalyzed by chromium (III)-salen catalysts proceed with exceptionally high enantioselectivity to afford highly functionalized cyclohexene derivatives.