Triflic Acid Functionalized Carbon@Silica Composite: Synthesis and Applications in Organic Synthesis; DFT Studies of Indeno[1, 2‐b]indole. Issue 7 (17th February 2020)

• Record Type: Journal Article
• Authors: Sharma, Shally; Sharma, Harsha; Sharma, Sukanya; Paul, Satya; Gupta, Vivek K.; Boukabcha, Nordine; Chouaih, Abdelkader
• Is Part Of: ChemistrySelect. Volume 5:Issue 7(2020)
• Page Start: 2201
• Page End: 2213
• Publication Date: 2020-02-17
• Subjects: Carbon@silica composite -- DFT -- Heterogeneous catalysis -- Single crystal X-ray crystallography -- Triflic acid; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201904727
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Triflic acid functionalized carbon@silica composite (CStar @SiO2 TfOH) was synthesized by the partial carbonization of starch in the presence of silica followed by the immobilization of triflic acid and its catalytic activity was explored for the three component synthesis of hexahydroacridine‐1, 8‐diones and indeno[1, 2‐ b ]indole‐9, 10‐diones. CStar @SiO2 ‐TfOH was characterized using different techniques, such as Fourier‐Transform Infrared Spectroscopy (FTIR), Thermogravimetricanalysis (TGA), X‐ray Powder Diffraction (XRD), Energy Dispersive X‐ray (EDX), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HR‐TEM) and was found to be recyclable upto five runs without any noticeable change. Further, the intermediate formed during the preparation of hexahydroacridine‐1, 8‐dione has been isolated and its structure was confirmed by single crystal X‐ray crystallography which confirms the proposed mechanism. Also, to confirm the structure of 4b, 9b‐dihydroxy‐5‐(4‐chlorophenyl)‐7, 7‐dimethyl‐4b, 5, 7, 8‐tetrahydroindeno[1, 2‐ b ]indole‐9, 10(6H, 9bH)‐dione we have performed the DFT study and found that the 1 H and 13 C chemical shift values and IR wavenumbers predicted by B3LYP method were very close to the experimentally determined values. Abstract : Novel solid acid catalyst, triflic acid functionalized carbon@silica composite (CStar @SiO2 ‐TfOH) for the three component synthesis of hexahydroacridine‐1, 8‐diones and indeno[1, 2‐b]indole‐9, 10‐diones in water under mild reaction conditions was developed. DFT study has been performed to confirm the structureof 4b, 9b‐dihydroxy‐5‐(4‐chlorophenyl)‐7, 7‐dimethyl‐4b, 5, 7, 8‐tetrahydroindeno[1, 2‐ b ]indole‐9, 10(6H, 9bH)‐dione, where experimental results correlate well with the theoretical data.