Correction: Nano Au/Pd-catalysed ‘on-water’ synthesis of C3–C3′ diaryl-oxindole scaffolds via N₂-selective dearomatization of indole

Abstract

Correction for ‘Nano Au/Pd-catalysed ‘on-water’ synthesis of C3–C3′ diaryl-oxindole scaffolds via N2-selective dearomatization of indole’ by Shivanee Borpatra Gohain et al., Green Chem., 2020, 22, 170–179, https://doi.org/10.1039/C9GC02370D.

Photoactivation of peroxymonosulfate (PMS) over a CuO–ZnO p–n heterojunction for the selective C2 trimerization of indoles

“…An analysis of the available literature was done before performing the reaction to find an adequate oxidant and solvent system. 6,7 For this kind of oxidative dearomatization reaction, various oxidants, namely, molecular oxygen (O 2 ), H 2 O 2 , TBHP, and peroxymonosulfate (PMS) were utilised. 6 Therefore, initially taking 8 mg of CuO-ZnO, 1 mmol of indole, and 1 mmol of each individual oxidant using aqueous acetonitrile (CH 3 CN) as solvent system, the reaction was screened for the suitable oxidant for the trimerization reaction.…”

“…From previous reports, it can be assumed that oxidants such as PMS, if can be activated in a proper solvent system, can bring substantial changes in the C2 trimerization of indoles. 7 Much recently, our own group has shown that a highly dispersed Fe 2 O 3 nano-catalyst on a zeolite-Y support could provide the C2-trimerized product at room temperature (RT). 6 Therefore, there is a large scope to design a reaction system that can activate PMS to exhibit such reaction under photocatalytic conditions.…”

“…Looking into the energy aspect and sustainability issues, finding a green protocol for similar types of reactions is highly encouraged. Most of the reported protocols required expensive metal catalysts (Pd and Au), 7 long reaction time (12–24 h), 8 high temperatures 3 and additives 5 for their successful completion. In this regard, hetero metal oxide (p–n) junctions can be promising candidates for this reaction considering the sustainable energy utilisation aspect.…”