Pd(OAc)2-Catalyzed, AgOAc-Promoted Z Selective Directed β-Arylation of Acrylamide Systems and Stereoselective Construction of Z-Cinnamamide Scaffolds
摘要:
A Pd(OAc)(2)-catalyzed, AgOAc-promoted and bidentate ligand-directed Z selective C-H activation, followed by the beta-arylation of the C(sp(2))-H bond of N-(quinolin-8-yl)acrylamide systems with aryl- and heteroaryl iodides, and a contemporary method for the construction of various Z-cinnamamides and beta,beta-diarylated acrylamides are reported. A plausible reaction mechanism comprising the bidentate ligand-aided, chelation-based C-H functionalization was proposed for the observed Z selective beta-arylation of N-(quinolin-8-yl)acrylamide systems.
Cobalt-Catalyzed, Aminoquinoline-Directed C(sp<sup>2</sup>)H Bond Alkenylation by Alkynes
作者:Liene Grigorjeva、Olafs Daugulis
DOI:10.1002/anie.201404579
日期:2014.9.15
A method for cobalt‐catalyzed, aminoquinoline‐ and picolinamide‐directed C(sp2)Hbondalkenylation by alkynes was developed. The method shows excellent functional‐group tolerance and both internal and terminal alkynes are competent substrates for the coupling. The reaction employs a Co(OAc)2⋅4 H2O catalyst, Mn(OAc)2 co‐catalyst, and oxygen (from air) as a terminal oxidant.
开发了一种钴催化、氨基喹啉和吡啶酰胺引导的炔烃 C(sp 2 ) H 键烯基化方法。该方法显示出优异的官能团耐受性,内部和末端炔烃都是偶联的有效底物。该反应采用Co(OAc) 2 ⋅4 H 2 O催化剂、Mn(OAc) 2助催化剂和氧气(来自空气)作为终端氧化剂。
Cobalt-Catalyzed Electrochemical Oxidative C–H/N–H Carbonylation with Hydrogen Evolution
for the carbonylation industry. Transition-metal-catalyzed oxidative C–H/C(X)–H carbonylation with CO provides one of the most straightforward approaches to construct carbonyl compounds. However, the use of stoichiometric oxidants would bring several drawbacks such as high cost and undesired chemical waste. Especially, the explosion limit is a potential safety hazard in oxidative carbonylation using
一氧化碳是羰基化行业中一种丰富且具有成本效益的C1构建基块。过渡金属催化的CO氧化C–H / C(X)–H羰基化反应是最简单的羰基化合物构建方法之一。然而,使用化学计量的氧化剂将带来一些缺点,例如高成本和不希望的化学废物。特别是,爆炸极限是在使用O 2作为氧化剂进行氧化羰基化反应中的潜在安全隐患。为克服这些问题,已经设计了一种利用阳极氧化来循环钴催化剂和H 2的氧化C–H / N–H羰基化的电化学方法。在阴极产生。分子内和分子间羰基化产物可以以良好的官能团耐受性获得,产率为31%–99%。通过XANES和CV的研究提出了一种可能的反应机理,该反应机理涉及Co II / Co III / Co I催化循环。
Synthesis of Chiral Spirolactams via Sequential C−H Olefination/Asymmetric [4+1] Spirocyclization under a Simple Co
<sup>II</sup>
/Chiral Spiro Phosphoric Acid Binary System
作者:Wen‐Kui Yuan、Bing‐Feng Shi
DOI:10.1002/anie.202108853
日期:2021.10.18
An unprecedented enantioselective synthesis of spiro-γ-lactams via a sequential C−H olefination/asymmetric [4+1] spirocyclization under a simple CoII/chiral spiro phosphoric acid (SPA) binary system is reported. A range of biologically important spiro-γ-lactams are obtained with high levels of enantioselectivity (up to 98 % ee). The concise, asymmetric synthesis of an aldose reductase inhibitor was
报道了在简单的 Co II /手性螺磷酸 (SPA) 二元体系下,通过连续的 C-H 烯化/不对称 [4+1] 螺环化,对螺-γ-内酰胺进行了前所未有的对映选择性合成。以高水平的对映选择性(高达 98% ee)获得了一系列生物学上重要的螺-γ-内酰胺。成功实现了醛糖还原酶抑制剂的简洁、不对称合成。值得注意的是,与之前依赖使用环戊二烯基或其衍生物(非手性 Cp*、Cp tBu或手性 Cp x)连接的 Co III 的报告相反 需要繁琐步骤来制备的复合物,廉价且可商购的四水合乙酸钴 (II) 被用作有效的预催化剂。
Selective C–C bond cleavage of amides fused to 8-aminoquinoline controlled by a catalyst and an oxidant
作者:Sen Li、Kun Jie、Wenjie Yan、Qingjun Pan、Min Zhang、Yufeng Wang、Zhengjiang Fu、Shengmei Guo、Hu Cai
DOI:10.1039/d0cc04960c
日期:——
Herein, copper-catalyzed direct C–C bond cleavage of amides fused to 8-aminoquinoline as a directing group to form urea in the presence of amines and dioxygen is reported. Compared to the previous C–H aminations of amides via C–H activation, this reaction presents a catalyst and oxidant controlled C–C bond cleavage strategy that enables amidation through a radical process. CuBr/Ag2CO3/O2 shows the
在本文中,据报道,在胺和双氧存在下,铜与8-氨基喹啉作为导向基团形成酰胺的铜催化直接C–C键裂解。与以前的通过C–H活化进行酰胺化的C–H胺相比,该反应提出了催化剂和氧化剂控制的C–C键裂解策略,可通过自由基过程进行酰胺化。CuBr / Ag 2 CO 3 / O 2在150°C下表现出最好的催化效果。一系列的芳基和烷基酰胺与该转化相容。值得注意的是,该方法提供了获得最重要的工业材料之一环己酮的途径。研究了该反应的途径。
Diastereoselective [3+2] Annulation of Aromatic/Vinylic Amides with Bicyclic Alkenes through Cobalt-Catalyzed C−H Activation and Intramolecular Nucleophilic Addition
dihydroepoxybenzofluorenone derivatives fromaromatic/vinylic amides and bicyclic alkenes is described. This new transformation proceeds through cobalt‐catalyzed C−H activation and intramolecular nucleophilic addition to the amide functional group. Transition‐metal‐catalyzed C−H activation reactions of secondary amides with alkenes usually lead to [4+2] or [4+1] annulation; to the best of our knowledge