Application of directed metalation in synthesis. Part 8: Interesting example of chemoselectivity in the synthesis of thioaurones and hydroxy ketones and a novel anionic ortho-Fries rearrangement used as a tool in the synthesis of thienopyranones and thiafluorenones
摘要:
Chemoselective synthesis of thioaurones or 3-hydroxy benzo[b]thiophen-2-aryl ketones, 1-hydroxy naphtho[2,1-b]thiophen-2aryl ketones and chalcones from N,N-diethyl-ortho-methyl sulfanyl aryl amides were described. (Benzo[b]thiophen-2-yl) alkylates and (naphtho[2, 1-b]thiophen-2-yl) alkylates undergo a novel anionic ortho-Fries rearrangement leading to (3-hydroxy benzo[b]thiophen-2-yl) and (1-hydroxy naphtho[2, 1 -b]thiophen-2-yl) alkyl ketones. The hydroxy ketones were used as intermediates in the synthesis of wide range of benzothienopyranones and thiafluorenones. (c) 2005 Elsevier Ltd. All rights reserved.
Reaction of<i>E</i>-2-arylidene-1-indanones, Z-aurones, Z-1-thioaurones and Z-2-arylidene-2,3-dihydro-1<i>H</i>-indol-3-ones with diazomethane
作者:Albert Lévai、Tamás Patonay
DOI:10.1002/jhet.5570360328
日期:1999.5
E-2-arylidene-1-indanones 1a-h and Z-aurones 3a-c with diazomethane provided trans-spiro-1-pyrazolines 2a-h and 4a-c, respectively, as sole products. However, the same cycloaddition of Z-1-thioaurones 5a-f afforded a mixture of Z-α-methyl-1-thioaurones 6a-f and trans-cyclopropane derivatives 7a-f as a result of the spontaneous denitrogenation of the initially formed 1-pyrazolines. Similar reaction of Z-2-arylidene-2
E -2-芳基-1-茚满酮1a-h和Z-金酮3a-c与重氮甲烷的1,3-偶极环加成分别提供反-螺-1-吡唑啉2a-h和4a-c作为唯一产物。然而,由于最初形成的化合物1的自发脱氮作用,Z-1-硫代金酮5a-f的相同环加成得到了Z-α-甲基-1-硫代金酮6a-f和反式环丙烷衍生物7a-f的混合物。-吡唑啉。Z-2-芳基-2,3-二氢-1 H-吲哚-3-酮8a,b与重氮甲烷的类似反应产生反式-环丙烷9a,b。通过核磁共振光谱测量已经阐明了合成化合物的结构和立体化学。
Dioxirane oxidation of (Z)-1-thioaurones, (E)-3-arylidene-1-thiochroman-4-ones and (E)-3-arylidene-1-thioflavan-4-ones
The oxidation of the title compounds 1, 4 and 7 with dimethyldioxirane (DMD) afforded the corresponding sulfoxides 2, 5 and 8 and/or sulfones 3, 6 and 9 in good yields (Scheme 1 and 2). Excess dimethyldioxirane gave the sulfones chemoselectively without formation of the epoxides. The epoxidation of the sulfones 6a,b,d to the respective spiroepoxides 10a,b,d required the more reactive methyl(trifluoromethyl)dioxirane
Cooperative Activating Effect of Tertiary Amine/DMSO on Elemental Sulfur: Direct Access to Thioaurones from 2′-Nitrochalcones under Mild Conditions
作者:Thanh Binh Nguyen、Pascal Retailleau
DOI:10.1021/acs.orglett.7b03547
日期:2018.1.5
A newmode for the activation of elemental sulfur is reported. In the presence of both DMSO and a tertiary aliphatic amine (triethylamine or N-methylpiperidine), this element reacts directly with a wide range of 2′-nitrochalcones 1 to provide the corresponding thioaurones 2 in high yields even at room temperature and in the absence of transitionmetal catalyst.
Synthesis of dispiro[1-benzothiophene-2,3'-pyrrolidine-2',3”-indoline]-2”,3-diones in cycloaddition reaction
作者:Ying Zhou、Yulin Huang、Guihua Tang、Xiaofang Li
DOI:10.1007/s10593-019-02575-6
日期:2019.11
cycloaddition of azomethine ylides derived from isatin and sarcosine to (Z)-2-(arylmethylidene)-1-benzothiophen-3(2H)- ones afforded novel dispiro[1-benzothiophene-2,3'-pyrrolidine-2',3”-indoline]-2”,3-diones in moderate yields. The structures of all the products were characterized by NMR, IR, HRMS together with X-ray crystallographic analysis. The reaction gives two diastereomeric products. This result is different