Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines

doi:10.1126/science.abb2559

GSTDTAP > 气候变化

DOI	10.1126/science.abb2559
	Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines
	Josep Mas-Roselló; Tomas Smejkal; Nicolai Cramer
	2020-06-05
发表期刊	Science
出版年	2020
英文摘要	Catalysts that add hydrogen to carbon-carbon, carbon-nitrogen, and carbon-oxygen double bonds are among the most widely used in synthetic chemistry. They are particularly adept at delivering just one of two mirror-image products. However, they may also target adjacent bonds in the compound that would be better left intact. Mas-Roselló et al. report that an iridium catalyst paired with a strong acid can hydrogenate C=N bonds without disturbing a weak N–O bond on the same nitrogen center. The reactions proceed at room temperature with high enantioselectivity. Science , this issue p. [1098][1] Asymmetric hydrogenations are among the most practical methods for the synthesis of chiral building blocks at industrial scale. The selective reduction of an oxime to the corresponding chiral hydroxylamine derivative remains a challenging variant because of undesired cleavage of the weak nitrogen-oxygen bond. We report a robust cyclometalated iridium(III) complex bearing a chiral cyclopentadienyl ligand as an efficient catalyst for this reaction operating under highly acidic conditions. Valuable N- alkoxy amines can be accessed at room temperature with nondetected overreduction of the N‒O bond. Catalyst turnover numbers up to 4000 and enantiomeric ratios up to 98:2 are observed. The findings serve as a blueprint for the development of metal-catalyzed enantioselective hydrogenations of challenging substrates. [1]: /lookup/doi/10.1126/science.abb2559
领域	气候变化 ; 资源环境
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/273441
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Josep Mas-Roselló,Tomas Smejkal,Nicolai Cramer. Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines[J]. Science,2020.
APA	Josep Mas-Roselló,Tomas Smejkal,&Nicolai Cramer.(2020).Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines.Science.
MLA	Josep Mas-Roselló,et al."Iridium-catalyzed acid-assisted asymmetric hydrogenation of oximes to hydroxylamines".Science (2020).