设计并合成了基于吡啶基序的手性吡咯二酰胺裂隙1和2,用于在溶胶-凝胶介质中手性识别羟基羧酸盐。在两个异构的手性受体中,受体1在其CH 3 CN中的镜像异构体上显示出酒石酸d-丁酯的选择性传感。异构体受体2在识别中没有显示任何对映选择性。此外,受体1通过凝胶验证了酒石酸d-酒石的迅速视觉感测。通过荧光,紫外可见,1 H NMR和CD光谱法研究了受体的识别特性。
设计并合成了基于吡啶基序的手性吡咯二酰胺裂隙1和2,用于在溶胶-凝胶介质中手性识别羟基羧酸盐。在两个异构的手性受体中,受体1在其CH 3 CN中的镜像异构体上显示出酒石酸d-丁酯的选择性传感。异构体受体2在识别中没有显示任何对映选择性。此外,受体1通过凝胶验证了酒石酸d-酒石的迅速视觉感测。通过荧光,紫外可见,1 H NMR和CD光谱法研究了受体的识别特性。
Enantioselectivealdolreactions of various isatins with ketones using newly designed amino amide organocatalysts were found to provide chiral 3-substituted 3-hydroxy-2-oxindoles in good to excellent yields and with excellent stereoselectivities (up to 99 %, up to 98 % ee, syn/anti = 99:1); one catalyst, 3i, proved particularly successful. One of the resulting oxindoles, 3-hydroxy-3-(2-oxocyclohexyl)-2-indolinone
Pyrrole-based tetra-amide for hydrogen pyrophosphate (HP<sub>2</sub>O<sub>7</sub><sup>3−</sup>) and F<sup>−</sup> ions in sol-gel medium
作者:Sumit Ghosh、Koushik Goswami、Kumaresh Ghosh
DOI:10.1080/10610278.2017.1348603
日期:2017.12.2
A simple pyrrole-based tetra-amide 1 shows selective fluorescence sensing of HP2O73- over a series of other anions in CH3CN by exhibiting excimer emission at similar to 450nm. In DMSO:CHCl3 (1:5 v/v), compound 1 forms gel that undergoes disintegration to sol in the presence of basic anions such as F-, AcO- and H2PO4-. However, the gel state of 1 under a particular condition is observed to be selective to F- over AcO- and H2PO4- anions. The recognition properties of the receptor have been studied by fluorescence, UV-vis and H-1 NMR spectroscopic methods.
Isomeric chiral pyrrole diamides and their efficacy in enantioselective sensing of tartrate in sol–gel medium
作者:Kumaresh Ghosh、Anupam Majumdar
DOI:10.1016/j.tetlet.2016.06.128
日期:2016.8
synthesized for chiral recognition of hydroxycarboxylates in sol–gel medium. Of the two isomeric chiral receptors, receptor 1 shows selective sensing of d-tetrabutylammonium tartrate over its mirrorimageisomer in CH3CN. The isomeric receptor 2 did not show any enantioselectivity in the recognition. Moreover, the receptor 1 validates prompt visual sensing of d-tartrate through gelation. The recognition
设计并合成了基于吡啶基序的手性吡咯二酰胺裂隙1和2,用于在溶胶-凝胶介质中手性识别羟基羧酸盐。在两个异构的手性受体中,受体1在其CH 3 CN中的镜像异构体上显示出酒石酸d-丁酯的选择性传感。异构体受体2在识别中没有显示任何对映选择性。此外,受体1通过凝胶验证了酒石酸d-酒石的迅速视觉感测。通过荧光,紫外可见,1 H NMR和CD光谱法研究了受体的识别特性。
Amino Amide Organocatalysts for Asymmetric Michael Addition of β-Keto Esters with β-Nitroolefins
Asymmetric Michaeladdition of β-ketoesters with trans-β-nitroolefins using chiral amino amide organocatalyst was tried and afforded synthetically useful chiral Michael adducts in both excellent c...