Synthesis of fused indoline heterocycles via dearomatization of indoles with α-bromohydrazones: a systematic study on the substrates
作者:Wen-Bin Cao、Xiao-Ping Xu、Shun-Jun Ji
DOI:10.1039/c6ob02362b
日期:——
An efficient metal-free dearomatization of indoles with α-bromohydrazones is reported. Various fused indoline heterocycles, which are potentially biologically active, were achieved in good yields (up to 94%) under mild conditions. A systematic study on electronic- and steric effects of substrate and reagents revealed that they have great influence upon the reaction. Based on this, the scope of indoles
Inverse Electron-Demand Aza-Diels–Alder Reaction of α,β-Unsaturated Thioesters with In Situ-Generated 1,2-Diaza-1,3-dienes for the Synthesis of 1,3,4-Thiadiazines
electron-demand aza-Diels–Alder reaction of α,β-unsaturated thioesters with 1,2-diaza-1,3-dienes generated in situ from α-halogeno hydrazones was developed. With α,β-unsaturated thioesters as C═S dienophiles, the developed protocol enables the formation of diverse 3,6-dihydro-2H-1,3,4-thiadiazine derivatives in excellent yields. In the presence of lithiumaluminumhydride, 3,6-dihydro-2H-1,3,4-thiadiazine
开发了α,β-不饱和硫酯与 α-卤代腙原位生成的 1,2-二氮杂-1,3-二烯的高度区域选择性逆电子需求氮杂-狄尔斯-阿尔德反应。以 α,β-不饱和硫酯作为 C=S 亲双烯体,所开发的方案能够以优异的收率形成多种 3,6-二氢-2 H -1,3,4-噻二嗪衍生物。在氢化铝锂的存在下,3,6-二氢-2 H -1,3,4-噻二嗪衍生物可以进一步转化为5,6-二氢-4 H -1,3,4-噻二嗪,收率良好。
Copper(I)-Catalyzed Asymmetric Desymmetrization through Inverse-Electron-Demand aza-Diels-Alder Reaction: Efficient Access to Tetrahydropyridazines Bearing a Unique α-Chiral Silane Moiety
作者:Liang Wei、Yu Zhou、Zhi-Min Song、Hai-Yan Tao、Zhenyang Lin、Chun-Jiang Wang
DOI:10.1002/chem.201700912
日期:2017.4.11
unprecedented copper(I)‐catalyzed asymmetric desymmetrization of 5‐silylcyclopentadienes with in situ formed azoalkene was realized through an inverse‐electron‐demand aza‐Diels–Alder reaction (IEDDA) pathway, in which 5‐silylcyclopentadienes served as efficient enophiles. This new protocol provides a facile access to the biologically important heterocyclic tetrahydropyridazines containing a unique α‐chiral
Photocatalytic radical cyclization of α-halo hydrazones with β-ketocarbonyls: facile access to substituted dihydropyrazoles
作者:Jing-miao Yu、Guo-Ping Lu、Chun Cai
DOI:10.1039/c7cc01470h
日期:——
A mild and efficient method for the photocatalytic radical cyclization of α-halo hydrazones with β-ketocarbonyls has been described. This strategy provides a potential protocol for the construction of functionalized 4,5-dihydropyrazoles in moderate to high yields.
Catalytic asymmetric inverse electron demand Diels–Alder reaction of fulvenes with azoalkenes
作者:Liang Wei、Qiao Zhu、Zhi-Min Song、Kang Liu、Chun-Jiang Wang
DOI:10.1039/c7cc09896k
日期:——
An unprecedented copper(I)-catalyzed asymmetric inverse electron demand Diels–Alderreaction of azoalkenes with fulvenes is reported. This methodology offers a directed entry to synthesize bicyclic tetrapyridazine derivatives in good yield with exclusive regioselectivity and excellent stereoselectivity.