Ruthenium-catalyzed cyclopropanation of alkenes using propargylic carboxylates as precursors of vinylcarbenoids
Ruthenium-catalyzed cyclopropanation of alkenes using propargylic carboxylates as precursors of vinylcarbenoids
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DOI：
10.1021/jo034841a
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发表时间：
2003-10-31
影响因子：
3.6
通讯作者：
Uemura, S
中科院分区：
文献类型：
--
作者：
Miki, K;Ohe, K;Uemura, S
在[RuCl_2（CO）（3）]（2）的催化下，不同烯烃与炔丙基羧酸酯1的分子间环丙烷化反应高产率地得到了乙烯基环丙烷2。该反应的关键中间体是通过羧酸酯的羰基氧亲核攻击由钌络合物活化的炔的内部碳而原位产生的乙烯基卡宾络合物。除了Ru化合物之外，各种过渡金属化合物也可用于该体系中。共轭二烯也进行类似的环丙烷化，得到反式-vic-二乙烯基环丙烷衍生物和环庚二烯衍生物5，后者是通过Cope型重排从最初形成的顺式-vic-异构体热衍生的。本反应在化学上等同于使用α-重氮酮作为类卡宾前体的过渡金属催化的环丙烷化反应。
Intermolecular cyclopropanation reactions of various alkenes with propargylic carboxylates 1 are catalyzed by [RuCl2(CO)(3)](2) to give vinylcyclopropanes 2 in good yields. The key intermediate of the reaction is a vinylcarbene complex generated in situ by nucleophilic attack of a carbonyl oxygen of the carboxylates to an internal carbon of the alkyne activated by the ruthenium complex. A variety of transition-metal compounds other than the Ru compound can also be employed in this system. Similar cyclopropanation proceeds with conjugated dienes as well to give trans-vic-divinylcyclopropane derivatives and cycloheptadiene derivatives 5, the latter being thermally derived from the initially formed cis-vic-isomers via Cope-type rearrangement. The present reaction is chemically equivalent to the transition metal-catalyzed cyclopropanation reaction using alpha-diazoketones as carbenoid precursors.