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.
Catalytic Asymmetric Synthesis of [2,3]-Fused Indoline Heterocycles through Inverse-Electron-Demand Aza-Diels-Alder Reaction of Indoles with Azoalkenes
作者:Min-Chao Tong、Xuan Chen、Jun Li、Rong Huang、Haiyan Tao、Chun-Jiang Wang
DOI:10.1002/anie.201400109
日期:2014.4.25
An unprecedented catalytic asymmetric inverse‐electron‐demand aza‐Diels–Alderreaction of indoles with in situ formed azoalkenes is reported. A diverse set of [2,3]‐fused indoline heterocycles were achieved in generally good yields (up to 97 %) with high regioselectivity and diastereoselectivity (>20:1 d.r.), and with excellent enantioselectivity (up to 99 % ee).
The catalytic asymmetric synthesis of tetrahydropyridazines via inverse electron-demand aza-Diels–Alder reaction of enol ethers with azoalkenes
作者:Liang Wei、Chun-Jiang Wang
DOI:10.1039/c5cc06465a
日期:——
A highly efficient catalytic asymmetric IEDDA reaction of azoalkenes with enol ethers is reported. This methodology provides a facile entry to biologically important tetrahydropyridazines in good yield with good to excellent ee.
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
Photoinduced [4 + 2]-cycloaddition reactions of vinyldiazo compounds for the construction of heterocyclic and bicyclic rings
作者:Ming Bao、Arnold R. Romero Bohórquez、Hadi Arman、Michael P. Doyle
DOI:10.1039/d4sc03558e
日期:——
vinyldiazoacetates with azoalkenes from α-halohydrazones, as well as with cyclopentadiene and furan, occurs with light irradiation at room temperature, producing highly functionalized heterocyclic and bicycliccompounds in good yields and excellent diastereoseletivity. Under blue light these vinyldiazoacetate reagents selectively form unstable cyclopropenes that undergo intermolecular cycloaddition reactions