Nickel-Catalyzed One-Pot Carbonylative Synthesis of 2-Mono- and 2,3-Disubstituted Thiochromenones from 2-Bromobenzenesulfonyl Chlorides and Alkynes
作者:Wei Wang、Zhi-Peng Bao、Xinxin Qi、Xiao-Feng Wu
DOI:10.1021/acs.orglett.1c02442
日期:2021.8.20
A nickel-catalyzed one-pot carbonylation reaction of 2-bromobenzenesulfonyl chlorides with alkynes for the synthesis of thiochromenones has been established. Both terminal and internal alkynes were suitable substrates in this carbonylative transformation, and a broad range of 2-mono- and 2,3-disubstituted thiochromenone products were obtained in moderate to good yields with quite high functional group
Conjugate Addition of Grignard Reagents to Thiochromones Catalyzed by Copper Salts: A Unified Approach to Both 2-Alkylthiochroman-4-One and Thioflavanone
作者:Tania J. Bellinger、Teavian Harvin、Ti’Bran Pickens-Flynn、Nataleigh Austin、Samuel H. Whitaker、Mai Ling C. Tang Yuk Tutein、Dabria T. Hukins、Nichele Deese、Fenghai Guo
DOI:10.3390/molecules25092128
日期:——
Grignard reagents undergo conjugateaddition to thiochromones catalyzed by copper salts to afford 2-substituted-thiochroman-4-ones, both 2-alkylthiochroman-4-ones and thioflavanones (2-arylthiochroman-4-ones), in good yields with trimethylsilylchloride (TMSCl) as an additive. The best yields of 1,4-adducts can be attained with CuCN∙2LiCl as the copper source. Excellent yields of 2-alkyl-substituted thiochroman-4-ones
Elemental Chalcogen (Se, S) in PEG-400 to the Synthesis of Seleno- and Thioflavones from 2-Chlorophenyl Ethynyl Ketone and Nucleophilic Species of Chalcogen
作者:Patrick Nobre、Thiago Peglow、Ricardo Bartz、Angelita Barcellos、Raquel Jacob、Márcio Silva、Thiago Barcellos、Gelson Perin
DOI:10.21577/0103-5053.20210051
日期:——
for the synthesis of thio- and selenoflavones by the ring closure of 2-chlorophenyl ethynyl ketone with NaHY (Y = S, Se). These nucleophilic chalcogen species were generated in situ using NaBH4 to reduce the elemental chalcogen in the presence of polyethylene glycol-400 (PEG-400). The efficiency of this reaction is strongly dependent on the PEG-400 solvent, acting like a crown ether, complexing with the
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)。
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