A new preparation of substituted 4<i>H</i>-1-benzothiopyran-4-ones from c(α)<i>N</i>-benzoylhydrazones or c(α)<i>N</i>-carboalkoxyhydrazones and methyl thiosalicylate
作者:Kristen L. French、April J. Angel、Angela R. Williams、Douglas R. Hurst、Charles F. Beam
DOI:10.1002/jhet.5570350109
日期:1998.1
C(α)N-Benzoylhydrazones or C(α),N-carboalkoxyhydrazones were dilithiated with excess lithium diisopropylamide, and the dianion-type intermediates were condensed with lithiated methylthiosalicylate, followed by cyclization/hydrolysis to substituted4H-1-benzothiopyran-4-ones (thioflavones/thiochromones).
用过量的二异丙基氨基锂将C(α)N-苯甲酰肼或C(α)N-羰基烷氧基hydr酮二锂化,将二价阴离子型中间体与锂化的硫代水杨酸甲酯缩合,然后环化/水解成取代的4 H -1-苯并噻吩并- 4-one(硫代黄酮/硫代色酮)。
Synthesis of Fluoromethylated Chromones and Their Heteroatom Analogues via Sodium Fluoromethanesulfinate-Enabled Direct Fluoromethylation
作者:Kaiyue Yang、Dongxue Yin、Yuli Sun、Zhifang Yang、Yadong Li、Lingzhi Xu、Yunfei Du
DOI:10.1021/acs.joc.3c02301
日期:2024.1.5
their heteroatom analogues were conveniently synthesized from the reaction of chromones and their heteroatom analogues with CF3SO2Na or HCF2SO2Na in the presence of tert-butyl hydroperoxide under mild conditions. A mechanistic pathway involving the generation of the electrophilic tri/difluoromethyl radical, followed with the radical substitution of chromones and their heteroatom analogues, was postulated
在叔丁基过氧化氢存在下,在温和条件下,通过色酮及其杂原子类似物与CF 3 SO 2 Na或HCF 2 SO 2 Na的反应,方便地合成了一系列具有生物学意义的三/二氟甲基化色酮及其杂原子类似物。假设了一种机械途径,涉及亲电子三/二氟甲基自由基的产生,然后是色酮及其杂原子类似物的自由基取代。
Transition metal free intramolecular S-arylation: one-pot synthesis of thiochromen-4-ones
作者:T.A. Jenifer Vijay、Kebbahalli N. Nandeesh、Goravanahalli M. Raghavendra、Kanchugarakoppal S. Rangappa、Kempegowda Mantelingu
DOI:10.1016/j.tetlet.2013.09.094
日期:2013.11
A convenient one-pot method for the synthesis of thiochromen-4-ones by the condensation of 2'-haloacetophenone and dithioesters at room temperature in the presence of NaH in DMF in moderate to good yields has been developed. The method involves unusual intramolecular S-arylation. The reaction is operationally facile, readily scalable and offers rapid entry into substituted chromene-4-ones. (C) 2013 Elsevier Ltd. All rights reserved.
Copper-Catalyzed One-Pot Synthesis of 2-Arylthiochromenones: An in Situ Recycle of Waste Byproduct as Useful Reagent
作者:Subramani Sangeetha、Govindasamy Sekar
DOI:10.1021/acs.orglett.8b03508
日期:2019.1.4
Copper-catalyzed one-pot synthesis of various 2-arylthiochromenones is developed using xanthate as an odorless sulfur source from easily acquirable 2′-halochalcones. This methodology demonstrates that the cross-coupled product thiochromanone synthesized from 2′-halochalcones (upstream reaction) is oxidized to thiochromenone (downstream reaction) in the same pot using waste byproduct (KI) of the first
Rh-catalyzed asymmetric hydrogenation of 2-substituted 4H-thiochromenes and 4H-chromenes was successfully developed. This method provided highly efficient access to a series of chiral 2-substituted thiochromanes and chromanes in high yields with excellent enantioselectivities (up to 99% yield, 86–99% ee). The obtained chiral 2-substituted thiochromane products were also successfully transformed to