HIGHLY EFFECTIVE CATALYTIC METHODS FOR YLIDE GENERATION FROM DIAZO-COMPOUNDS - MECHANISM OF THE RHODIUM-CATALYZED AND COPPER-CATALYZED REACTIONS WITH ALLYLIC COMPOUNDS
HIGHLY EFFECTIVE CATALYTIC METHODS FOR YLIDE GENERATION FROM DIAZO-COMPOUNDS - MECHANISM OF THE RHODIUM-CATALYZED AND COPPER-CATALYZED REACTIONS WITH ALLYLIC COMPOUNDS
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DOI：
10.1021/jo00338a008
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发表时间：
1981-01-01
影响因子：
3.6
通讯作者：
BAGHERI, V
中科院分区：
文献类型：
--
作者：
DOYLE, MP;TAMBLYN, WH;BAGHERI, V
描述了乙酸铑 (II) 和十六羰基六铑对于重氮化合物与烯丙基甲基硫、代表性烯丙基叔胺和烯丙基卤化物反应中叶立德生成的催化效果。观察到由重氮乙酸乙酯和烯丙基硫醚、胺或碘化物产生的叶立德中间体的[2, 3] σ重排衍生的产物的排他性形成。重氮丙二酸二乙酯或重氮乙酸乙酯与烯丙基氯的反应中环丙烷化占主导地位，而环丙烷化和叶立德重排之间的竞争在与烯丙基溴的反应中表现出。烯丙基碘和烯丙基甲基硫醚拦截假定的类胡萝卜素中间体的能力非常相似。在与烯丙基溴和氯化物的反应中，与铑催化相比，铜催化导致叶立德衍生产物的产率显着高于环丙烷产物。与巴豆基溴的反应进一步例证了铑和铜化合物的催化差异，并确定了金属相关叶立德中间体的替代转化。环丙烷化和金属叶立德形成被表示为竞争过程。金属从金属缔合叶立德中间体解离产生反应性烯丙基叶立德，其发生[2, 3] σ重排。然而，据观察，在重氮基乙酸乙酯与巴豆基溴的铜催化反应中，由烯丙基转移到金属上的金属缔合叶立德重排所衍生的产物占主导地位。在 25°C 或以下进行的乙酸铑 (II) 催化反应中没有观察到这些相同的产物。
The catalytic effectiveness of rhodium (II) acetate and hexadecacarbonylhexarhodium for ylide generation in reactions of diazo compounds with allyl methyl sulfide, representative allylictertiary amines, and allyl halides is described. Exclusive formation of products derived from the [2, 3] sigmatropic rearrangement of ylide intermediates generated from ethyl diazoacetate and allyl sulfides, amines, or iodides is observed. Cyclopropanation is dominant in reactions of either diethyl diazomalonate or ethyl diazoacetate with allyl chloride, and competition between cyclopropanation and ylide rearrangement is exhibitedin reactions with allyl bromide. Allyl iodide and allyl methyl sulfide are very similar in their ability to interceptthe presumed carbenoid intermediates. Copper catalysis results in significantly higheryields of ylide-derived products, relative to cyclopropane products, than does rhodium catalysis in reactions with allyl bromides and chlorides. Reactions with crotyl bromide further exemplify the catalytic dissimilarities of rhodium and copper compounds and identify alternative transformations of metal-associated ylide intermediates. Cyclopropanation and metal ylideformation are represented as competing processes. Metal dissociation from themetal-associated ylide intermediate produces a reactive allylic ylide that is subject to the [2, 3] sigmatropic rearrangement. However, products derived from rearrangement of the metal-associated ylide byallyl group transfer to the metal are observed to predominate in copper-catalyzed reactions of ethyl diazoacetate with crotyl bromide. These same products are not observed in rhodium (II) acetate catalyzed reactions performed at or below 25 C.