Highly Z-Selective Double Bond Transposition in Simple Alkenes and Allylarenes through a Spin-Accelerated Allyl Mechanism.
Highly Z-Selective Double Bond Transposition in Simple Alkenes and Allylarenes through a Spin-Accelerated Allyl Mechanism.
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DOI：
10.1021/jacs.1c00856
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发表时间：
2021-03-03
影响因子：
15
通讯作者：
Holland PL
中科院分区：
文献类型：
--
作者：
Kim D;Pillon G;DiPrimio DJ;Holland PL
烯烃中的双键转位（异构化）为生物活性分子的合成提供了机会，但需要高选择性以避免产物的混合物。z -烯烃的生成，存在于许多天然产物和药物中，通常在热力学上相对于它们的E异构体是不利的，这使得它们特别具有挑战性。我们报道了一种β- dialdiminal -supported，高自旋钴(I)配合物，它可以转化末端烯烃，包括以前顽固的烯丙苯，以前所未有的高区域选择性和立体选择性为z -2-烯烃。氘标记研究表明，该催化剂通过π-烯丙基机制起作用，不同于其他选择性z催化剂遵循的烷基机制。计算表明，三态钴(I)烯烃配合物在C-H活化过渡态中从静止态三态转变为单线态，从而产生Z产物，这种自旋态的变化使催化剂能够区分立体限定势垒。这表明自旋状态的改变为第一排过渡金属的新型立体控制方法提供了一条途径。
Double-bond transposition in alkenes (isomerization) offers opportunities for the synthesis of bioactive molecules, but requires high selectivity to avoid mixtures of products. Generation of Z-alkenes, which are present in many natural products and pharmaceuticals, are usually thermodynamically disfavored relative to their E isomers which makes them particularly challenging. We report a β-dialdiminate-supported, high-spin cobalt(I) complex that can convert terminal alkenes, including previously recalcitrant allylbenzenes, to Z-2-alkenes with unprecedentedly high regioselectivity and stereoselectivity. Deuterium labeling studies indicate that the catalyst operates through a π-allyl mechanism, which is different than the alkyl mechanism that is followed by other Z-selective catalysts. Computations indicate that the triplet cobalt(I) alkene complex undergoes a spin state change from the resting-state triplet to a singlet in the C–H activation transition state leading to the Z product, and that this change in spin state enables the catalyst to differentiate the stereodefining barriers. This suggests that spin-state changes offer a route toward novel stereocontrol methods for first-row transition metals.
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影响因子：
2.8
作者：
Gonzalez-Fernandez, Rebeca;Crochet, Pascale;Cadierno, Victorio
通讯作者：
Cadierno, Victorio
钴催化的烯烃 Z 至 E 异构化：制备 (E)-β-取代苯乙烯的方法
影响因子：
5.2
作者：
Liu, Hongmei;Xu, Man;Xia, Yuanzhi
通讯作者：
Xia, Yuanzhi
影响因子：
56.9
作者：
Kapat, Ajoy;Sperger, Theresa;Schoenebeck, Franziska
通讯作者：
Schoenebeck, Franziska
影响因子：
4.1
作者：
Kobayashi, Tsuneyuki;Yorimitsu, Hideki;Oshima, Koichiro
通讯作者：
Oshima, Koichiro
DOI：
10.1007/bf01455466
发表时间：
1988-04-01
期刊：
BULLETIN OF THE ACADEMY OF SCIENCES OF THE USSR DIVISION OF CHEMICAL SCIENCE
影响因子：
--
作者：
GVINTER, LI;BORUNOVA, NV;SHARF, VZ
通讯作者：
SHARF, VZ