Nitrogen-containingheterocycles are especially considered “privileged” structural scaffolds for the development of new drugs. However, traditional methods of organic synthesis are mainly based on thermal cycloaddition reaction; thus, the exploration of new strategies for the rapid assembly of N-heterocycles under mild conditions is highly desirable. Here, we developed a new method that visible light
Formal [4 + 1] cycloaddition of <i>in situ</i> generated 1,2-diaza-1,3-dienes with diazo esters: facile approaches to dihydropyrazoles containing a quaternary center
作者:Bo Chen、Wen-Dao Chu、Quan-Zhong Liu
DOI:10.1039/c8ra08909d
日期:——
A Cu(ii)/bisoxazoline ligand-promotes the formal [4 + 1] cycloaddition of diazo esters with azoalkenes formed in situ. This provides a protocol for construction of dihydropyrazoles containing a quaternary center with good to excellent yields.
Copper(II)-Catalyzed Asymmetric 1,3-Dipolar [3+4] Cycloaddition and Kinetic Resolution of Azomethine Imines with Azoalkenes
作者:Liang Wei、Zuo-Fei Wang、Lu Yao、Guofu Qiu、Haiyan Tao、Hua Li、Chun-Jiang Wang
DOI:10.1002/adsc.201600961
日期:2016.12.22
copper(II)‐catalyzedenantioselective 1,3‐dipolar [3+4] cycloaddition of azomethineimines with in situ formed azoalkenes has been realized. This strategy provides a facile access to biologically important 1,2,4,5‐tetrazepine derivatives in high yield with exclusive regioselectivity and high stereoselectivity. Moreover, enantioenriched azomethineimines could be obtained via an efficient kinetic resolution
Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes
作者:Wenqing Hao、Long Wang、Jinlei Zhang、Dawei Teng、Guorui Cao
DOI:10.3762/bjoc.20.29
日期:——
Abstract A simple and efficient method for the synthesis of spiropyridazine-benzosultams has been developed by means of [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes. This approach displays advantages such as mild reaction conditions, wide substrate range tolerance, simple operation, compatibility with gram-scale preparation. Beilstein J. Org.
抽象的 通过3-取代苯并异噻唑1,1-二氧化物与1,2-二氮杂-1,3-二烯的[4+2]环化反应,开发了一种简单有效的螺哒嗪苯并磺内酰胺合成方法。该方法具有反应条件温和、底物耐受范围宽、操作简单、适合克级制备等优点。 Beilstein J. Org. Chem. 2024, 20, 280–286. doi:10.3762/bjoc.20.29
Copper‐Catalyzed Enantioselective Inverse Electron‐Demand Hetero‐Diels–Alder Reactions of Diazadienes with Enol Ethers: Efficient Synthesis of Chiral Pyridazines
AbstractA highly efficient and enantioselective inverse electron‐demand hetero‐Diels–Alder reaction of in situ generated 1,2‐diaza‐1,3‐dienes with enol ethers has been developed with the use of a chiral copper/bisoxazoline complex as the catalyst. The reaction exhibits high enantioselectivity (up to 90% ee) and provides a robust and powerful method to synthesize a variety of structurally diverse and densely substituted chiral pyridazine derivatives in good to excellent yields.magnified image