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。
Copper-Catalyzed 8-Aminoquinoline-Directed Selenylation of Arene and Heteroarene C–H Bonds
作者:Anup Mandal、Harekrishna Sahoo、Mahiuddin Baidya
DOI:10.1021/acs.orglett.6b01420
日期:2016.7.1
An efficient copper-catalyzed/-mediated and 8-aminoquinoline-assisted arylselenylation of inert C–H bonds of (hetero)arenes with readily available diselenides has been reported. The reaction is scalable and tolerates a wide spectrum of functional groups to deliver diarylselenides in very high yields (up to 98%). Application of this methodology to the facile synthesis of thiophene-fused selenochromone
achieved via a mild electrochemical oxidative CH/NH functionalization/intramolecular annulations with isocyanides in undivided cell equipped with a nickel cathode. In the presence of earth abundant cobalt catalyst, versatile iminoisoindolinone derivatives obtained in good yields and in a sustainable manner by using electricity as an oxidant in place of stoichiometric amount of silver and copper salts.
在配备镍阴极的未分隔电池中,通过温和的电化学氧化C H / N H功能化/分子间环化反应与异氰化物,已实现了功能化亚氨基异吲哚啉酮衍生物的有效合成。在富含土的钴催化剂的存在下,通过使用电代替化学计量的银和铜盐作为氧化剂,可以以高收率和可持续的方式获得通用的亚氨基异吲哚啉酮衍生物。
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
convenient copper-catalyzed method has been developed to achieve direct ortho-C–H/N-H annulation to synthesize phenanthridinones with arynes. This method highlights an emerging strategy to transform inert C–H bonds into versatile functional groups in organic synthesis and provides a new way to synthesize phenanthridinone alkaloids efficiently.