A mild and efficient protocol for the synthesis of 2,2′-difunctional biaryls from readily available benzamides and oximes by Co(OAc)2·4H2O catalysis has been developed. The catalytic cycle that includes aerobic oxidation of Co(I) to Co(III) is successfully achieved for the first time through dual-chelation-assisted C–H/C–H coupling with the assistance of catalytic Mn(acac)3. The catalytic system exhibits
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。
Highly regioselective and stereoselective synthesis of C-Aryl glycosides <i>via</i> nickel-catalyzed <i>ortho</i>-C–H glycosylation of 8-aminoquinoline benzamides
C-Arylglycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr–H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C–H activation could be the rate-determining
C-芳基糖苷作为候选药物具有很高的价值。本文描述了一种新颖且经济高效的镍催化邻-C Ar -H 糖基化反应,具有高区域选择性和优异的 α-选择性。该方法与各种糖苷表现出良好的官能团相容性,显示出其合成潜力。机理研究表明 C-H 激活可能是速率决定步骤。
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。
Nickel-Catalyzed Reaction of Benzamides with Bicylic Alkenes: Cleavage of C–H and C–N Bonds
作者:Aymen Skhiri、Naoto Chatani
DOI:10.1021/acs.orglett.9b00351
日期:2019.3.15
The nickel-catalyzed reaction of aromatic amides that contain an 8-aminoquinoline as a directing group with bicyclic alkenes, such as norbornene and 1,4-dihydro-1,4-epoxynaphthalene, results in the cleavage of both the C–H bond at the ortho-position of the benzene ring and the C(O)–N bond to give methanofluoren-9-one and 1,4-epoxyfluoren-9-one derivatives. Both Ni(OTf)2 and Ni(cod)2 show a high catalytic