Mohit L. Deb

Copper catalyzed oxidative deamination of Betti bases: an efficient approach for benzoylation/formylation of naphthols and phenols

An efficient route for benzoylation or formylation of naphthols/phenols is developed via oxidative deamination of Betti bases. A copper salt catalyst with TBHP as an oxidant is used. Water is used as a reagent as well as solvent. The reaction proceeds through a regioselective radical pathway. Most importantly, the position of acylation is unambiguous. The method is also applicable to non-hydroxy substrates.

Catalyst-free multi-component cascade C–H-functionalization in water using molecular oxygen: an approach to 1,3-oxazines

Herein, catalyst-free 3-component reactions of naphthols, aldehydes, and tetrahydroisoquinolines to synthesize 1,3-oxazines is reported. The reaction is performed in H2O in the presence of O2 as the sole oxidant at 100 °C, which proceeds through the formation of 1-aminoalkyl-2-naphthols followed by selective α-C–H functionalization of tert-amine.

C-C Bond Cleavage: Metal-Free-Catalyzed Reaction of Betti Bases with Various Heterocycles Under Microwave Irradiation

ABSTRACT The reaction of Betti bases with various heterocycles in the presence of p-toluenesulphonic acid (PTSA) under microwave irradiation gives bis(heterocycle)methanes through benzyl transfer. The reaction proceeds via the cleavage of C-N bond followed by C-C bond. The metal-free cleavage of C-C bond, which is in fact a C-dearylation, is rarely reported in the literature. GRAPHICAL ABSTRACT

CAN-catalyzed microwave promoted reaction of indole with Betti bases under solvent-free condition and evaluation of antibacterial activity of the products

ABSTRACT CAN-catalyzed reaction of Betti bases with indoles under microwave irradiation gives 3-(α,α-diarylmethyl)indoles. Better yield of the products, especially when one of the aryl ring is phenol were achieved. The reaction is performed in solvent-free condition. The antibacterial studies of the synthesized compounds were performed and some of the compounds showed good activity against Methicillin-resistant Staphylococcus aureus bacteria. GRAPHICAL ABSTRACT

One-pot sequential multi-component reaction: Synthesis of 3-substituted indoles

Abstract Here, we have developed a 3-component one-pot sequential approach to 3-substituted indoles. The main advantages of this process are step economy, reduced waste, and operational simplicity. The method involves in situ generation of 3-indolylalcohols from the reaction of indoles and aldehydes in the presence of base. Further, nucleophilic substitution of 3-indolylalcohols with various nucleophiles affords 3-substituted indole derivatives. The reaction does not requires any hazardous and expensive metal catalyst. In addition, the reaction is carried out in (1:1) ethanol–water which is considered as environmentally benign solvent. On the other hand, nonsequential 3-component reaction results in the formation of unwanted bisindolylmethanes. Graphical Abstract

A revisit to the multi-component reaction of indole, aldehyde, and N-substituted aniline catalyzed by PMA–SiO2

PMA–SiO2-catalyzed multi-component reaction of indole, aromatic aldehyde, and N-substituted aniline at room temperature under solvent-free condition is reported here. The reaction was previously reported, where a C–C and C–N bond were formed. However, we established a different structure for the product with the help of NMR as well as single-crystal X-ray studies, where the C-4 atom of N-substituted aniline is linked to the aldehydic carbon, and consequently, two new C–C bonds are formed. The mechanism of the reaction is established through trapping of the intermediate which is also different from the previous report. To the best of our knowledge, only one report is available in the literature for the synthesis of this class of important compounds.Graphical abstract