Iridium-catalyzed <em>Z</em>-retentive asymmetric allylic substitution reactions

doi:10.1126/science.abd6095

GSTDTAP > 气候变化

DOI	10.1126/science.abd6095
	Iridium-catalyzed Z-retentive asymmetric allylic substitution reactions
	Ru Jiang; Lu Ding; Chao Zheng; Shu-Li You
	2021-01-22
发表期刊	Science
出版年	2021
英文摘要	Transition metal catalysis offers a versatile means of modifying carbon centers adjacent to carbon-carbon double bonds. However, in the course of these reactions, the double bond tends to get weakened, allowing its substituents to swivel back and forth. Thus, if two large groups start out on the same side of the bond axis (a geometry known as a Z -olefin), they end up on opposite sides in the product. Jiang et al. report a chiral iridium catalyst that prevents this swiveling just long enough to substitute the adjacent carbon enantioselectively (see the Perspective by Malcolmson). Science , this issue p. [380][1]; see also p. [345][2] Z -Olefins are challenging synthetic targets owing to their relative thermodynamic instability. Transition metal–catalyzed asymmetric allylic substitution reactions are well known for installing stereocenters adjacent to branched or E -linear olefins. However, analogous reactions for the synthesis of optically active Z -olefin products are rare. Here we report iridium-catalyzed asymmetric allylic substitution reactions that retain Z -olefin geometries while establishing an adjacent quaternary stereocenter. The formation of transient anti -π-allyl-iridium intermediates and their capture by external nucleophiles before isomerization to the thermodynamically more stable syn -π-allyl-iridium counterparts have been observed. These results provide a promising method for preparing chiral Z -olefinic compounds. [1]: /lookup/doi/10.1126/science.abd6095 [2]: /lookup/doi/10.1126/science.abf8851
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/312364
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Ru Jiang,Lu Ding,Chao Zheng,et al. Iridium-catalyzed Z-retentive asymmetric allylic substitution reactions[J]. Science,2021.
APA	Ru Jiang,Lu Ding,Chao Zheng,&Shu-Li You.(2021).Iridium-catalyzed Z-retentive asymmetric allylic substitution reactions.Science.
MLA	Ru Jiang,et al."Iridium-catalyzed Z-retentive asymmetric allylic substitution reactions".Science (2021).