考虑到手性烯丙基胺结构基序的重要性以及合成方法对其构建的稀有性,在此,我们报道了Cp X Rh(III)催化的N对1,3-二烯的对映选择性分子间碳氨基化反应-苯氧基酰胺衍生的分子间芳基C–H活化和分子内酰胺转移。该方法可以嵌入酚官能团,直接合成多种手性烯丙基胺,并在温和条件下进行,形成顺序完整的区域选择性C–C键和高度对映选择性C–N键。综合的实验和计算机理研究揭示了一种不寻常的Rh(III)–Rh(I)–Rh(III)催化途径,其中烯烃插入/π-烯丙基化/分子内亲核取代级联参与该转化。此外,还证明了在天然产物的衍生和生物活性复合物的后期组装中的合成应用,这进一步增强了该方法的合成效用。
高价的环戊二烯基钴催化是实现可持续CH键功能化的通用工具。为了充分利用这种策略的潜力,必须控制这些过程的立体选择性。在本文中,我们报道了通过配备有手性环戊二烯基(Cp x)配体的Co III络合物催化的N苯氧酰胺的C H活化,对烯烃进行高度对映选择性的分子间碳胺化反应。该方法可在非常温和的条件下将广泛使用的丙烯酸酯以及双环烯烃转化为有吸引力的对映体富集的异酪氨酸衍生物,以及经过精制的氨基取代的双环支架。概述的反应性是Cp x Co III特有的 与4d和5d贵金属催化剂的反应性互补。
cobalt(III)-catalyzed, redox-neutral, intermolecular carboamination of propiolates and bicyclic alkenes was developed. This non-annulative coupling strategy features atom economy, high regioselectivity, good yields, and functional groups tolerance. Such a carboamination reaction was applied to modified phenolsfrom the corresponding phenols under mild conditions.
diazo compounds via a Rh(III)-catalyzed C-H activation, and the resulting Rh(III) intermediate subsequently undergoes an intramolecular oxidative addition into the O-N bond to form a Rh(V) nitrenoid species that is protonated and further directed toward electrophilic addition to the second ortho position of the phenyl ring. This work might provide a new direction for unsymmetrical C-H difunctionalization
The synthesis of heterocycles relies heavily on diverse sigmatropic rearrangements triggered by the cleavage of X–Y (X, Y = C, O, N, S, I) bonds. However, a unified rearrangement approach for constructing heterocyclic libraries is highly desirable. Encouraged by computational analysis of [3,3]-sigmatropic rearrangements, we can now rapidly synthesize oxa-heterocycles by treating N-phenoxyacetamides
Rh(III)-Catalyzed C–H Activation/[3 + 2] Annulation of <i>N</i>-Phenoxyacetamides via Carbooxygenation of 1,3-Dienes
作者:Liexin Wu、Liping Li、Haiman Zhang、Hui Gao、Zhi Zhou、Wei Yi
DOI:10.1021/acs.orglett.1c00945
日期:2021.5.21
C–H activation/[3 + 2] annulation of N-phenoxyacetamides has been developed for the construction of dihydrobenzofurans via carbooxygenation of 1,3-dienes. This transformation features a redox-neutral process with specific chemoselectivity, good substrate/functional group compatibility, and profound synthetic potentials. A preliminary exploration to realize their asymmetricsynthesis have been also successfully
Rhodium‐Catalyzed Atroposelective Access to Axially Chiral Olefins via C−H Bond Activation and Directing Group Migration
作者:Ruijie Mi、Haohua Chen、Xukai Zhou、Nan Li、Danqing Ji、Fen Wang、Yu Lan、Xingwei Li
DOI:10.1002/anie.202111860
日期:2022.1.3
Two classes of tetrasubstituted axially chiral olefins have been accessed in excellent enantioselectivity via RhIII-catalyzed asymmetric C−Hactivation assisted by a migratable directinggroup.