Tosylhydrazine mediated conjugate reduction and sequential reductive coupling cyclization: synthesis of 2-arylchromans
摘要:
Tosylhydrazine mediated conjugate reduction of 2-hydroxyl chalcones and sequential reductive coupling cyclization is described. This is an unprecedented protocol and an extremely efficient method for a one-pot domino synthesis of 2-arylchromans in good to excellent yields from commercially available, cheap starting materials. More importantly, the two-step reactions can be easily controlled to afford dihydrochalcones or 2-arylchromans by the mole amounts of tosylhydrazine. Furthermore, the operational simplicity of the process and the high functional group tolerance are remarkable. (C) 2015 Elsevier Ltd. All rights reserved.
A highly efficient and stereoselective synthesis of coumarin-, 1,3-cyclohexanedione-, and 1,4-naphthoquinone-fused 2,8-dioxabicyclo[3.3.1]nonanes is described. This was achieved via a sequential Michael addition/bicyclizationreaction from easily accessible 3-(2-hydroxyphenyl)-1-phenylprop-2-en-1-one derivatives. Three chemical bonds (one C–C bond and two C–O bonds), two six-membered cycles, and two
Reaction of ethyl acetoacetate and 2′-hydroxychalcones: Efficient route to 9-aryl-6<i>H</i>-benzo[c]chromen-6-ones
作者:I. B. Masesane、O. Mazimba
DOI:10.4314/bcse.v28i2.12
日期:——
The reaction of ethyl acetoacetate and 2′-hydroxychalcones under atmospheric air to furnish a series of functionalized 6H-benzo[c]chromen-6-ones in moderate yields is reported. The reaction proceeds through trans-esterification, intra-molecular Michael addition, Robinson annulation and oxidative aromatization.
An unexpected multi-component one-pot cascade reaction to access furanobenzodihydropyran-fused polycyclic heterocycles
作者:Jiaomei Guo、Hongjie Miao、Yang Zhao、Xuguan Bai、Yanshuo Zhu、Qilin Wang、Zhanwei Bu
DOI:10.1039/c9cc02170a
日期:——
es has been developed to afford an array of new furanobenzopyran-fused polycyclic compounds with complex molecular architectures. This reaction not only establishes a new reaction mode of ortho-hydroxychalcones but also provides an expedient and convenient synthetic strategy to access complex furanobenzopyran-fused heterocycles.
A Brønsted Acid‐Catalyzed Michael Addition/Cyclization Sequence for the Diastereoselective Assembly of Chroman‐Bridged Polycyclic Isoindolinones
作者:Shaojing Jin、Jia Guo、Dongmei Fang、Yongwei Huang、Qilin Wang、Zhanwei Bu
DOI:10.1002/adsc.201801227
日期:2019.2
The first p‐TSA‐catalyzed highly diastereoselective Michael addition/cyclization of 3‐carboxylate‐substituted isoindolinones and ortho‐hydroxychalcones was developed to access a wide range of chroman‐bridgedpolycyclic isoindolinones. This reaction represents a novel and efficient method for the construction of complex bridgedpolycyclic isoindolinones. Moreover, several derivatizations were carried