Isatins 3-C annulation vs ring-opening: Two different pathways for synthesis of spiro compounds via multicomponent reactions
作者:Qingqing Niu、Junhua Xi、Lei Li、Li Li、Chengli Pan、Meijun Lan、Liangce Rong
DOI:10.1016/j.tetlet.2019.151181
日期:2019.10
through the ring-opening of isatins process. The structures of spiro[indoline-3,4′-isoxazolo[5,4-b]pyrazolo[4,3-e]pyridin]-2-one, spiro[isoxazolo[5,4-b]quino line-4,5′-pyrrolo[2,3-d]pyrimidine]-2′,4′,6′(1′H,3′H,7′H)-trione, and spiro[indoline-3,4′-pyrazolo[3,4-b]pyridine]-2,6′(5′H)-dione were successfully confirmed by 1H NMR, 13C NMR, HRMS, and X-ray crystal diffraction analysis.
通过两种不同的途径从靛红,3-苯基异恶唑-5(4 H)-一个(3-乙基异恶唑-5(4 H)-一个)和吡唑-5-胺(6-报道了氨基嘧啶-2,4(1 H,3 H)-二酮)。催化剂Amberlyst-15易于回收利用,可重复使用许多次,而催化活性没有任何明显的损失。新型螺环化合物是通过isatins开环过程获得的。螺[吲哚啉-3,4'-异唑并[5,4- b ]吡唑并[4,3-e]吡啶] -2-one,螺[异唑并[5,4 - b ]喹啉-4, 5′-吡咯并[2,3- d ]嘧啶] -2′,4′,6′(1′H,3′H,7′H)-三酮和螺[吲哚啉-3,4′-吡唑并[ 3,4-通过1 H NMR,13 C NMR,HRMS和X射线晶体衍射分析成功地确定了b ]吡啶] -2,6'(5'H)-二酮。
Iodine-catalyzed synthesis of sulfonyl isoxazoles from sodium sulfinates and isoxazol-5(4H)-ones
作者:Dong Tang、Zafar Iqbal、Jian Sun、Jingwen Ji、Minghua Yang、Zhixiang Yang
DOI:10.1016/j.tetlet.2020.152685
日期:2021.1
An efficient I2-mediated sulfonylation at 4-position of isoxazoles has been developed by employing sodium sulfinate and 3-substituted isoxazol-5(4H)-ones. This metal-free, one-pot strategy provides various sulfonyl isoxazoles under mild reaction conditions. The final product exists in the form of stable organic sodium salt, which can be purified by column chromatography under air.
pyrimido[1,2-a]indol-4-ol heteroarenes via a Cp*Rh(III)-catalyzed cascade C−Hactivation/annulation strategy employing N-methoxyindoleamides and isoxazolones is developed. Also, a framework of 3-methoxy-2,3-dihydro-[1,3,5]triazino[1,2-a]indole-4,10-dione was successfully synthesized via a Cp*Rh-catalyzedC−Hactivation/annulation/oxidation reaction between N-(methyloxy)-1H-indole-1-carboxamide and isoxazolones