Intermolecular transition metal-catalyzed [4+2+2] cycloaddition reactions: A new approach to the construction of eight-membered rings
Intermolecular transition metal-catalyzed [4+2+2] cycloaddition reactions: A new approach to the construction of eight-membered rings
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DOI：
10.1021/ja026351q
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发表时间：
2002-07-31
影响因子：
15
通讯作者：
Fazal, AN
中科院分区：
文献类型：
--
作者：
Evans, PA;Robinson, JE;Fazal, AN
过渡金属催化的环加成反应是构建复杂多环体系的有效方法。我们开发了一种新的分子间金属催化的杂原子链烯炔衍生物与1，3-丁二烯的[4+2+2]环加成反应。本研究表明，通过合理选择银盐，杂环加成加合物可以获得良好的选择性。稀土金属催化的烯丙基取代[4+2+2]环加成反应的发展提供了一种方便的三组分偶联反应，绕过了烯炔衍生物的先前形成。最后，在C-2位引入立体中心导致了非对映选择性环加成反应，这为构建适用于目标定向合成的双环辛烷环系提供了一种强有力的新方法。
Transition metal-catalyzed cycloaddition reactions represent powerful methods for the construction of complex polycyclic systems. We have developed a newintermolecular metal-catalyzed [4 + 2 + 2] cycloaddition of heteroatom-tethered enyne derivatives with 1,3-butadiene. This study demonstrates that excellent selectivity can be obtained for theheterocycloaddition adducts through the judicious choice of silver salt. The development of thetandemrhodium-catalyzed allylic substitution [4 + 2 + 2] cycloaddition provides a convenient three-component coupling that circumvents the prior formation of the enyne derivative. Finally, the introduction of a stereogenic center at C-2 leads to a diastereoselective cycloaddition, which provides a powerful new method for the construction of bicyclic octanoid ring systems applicable to target directed synthesis.