Nandita Ghosh

Dry reaction of indoles with carbonyl compounds on montmorillonite K10 clay: a mild, expedient synthesis of diindolylalkanes and vibrindole A

Abstract Dry reaction of indoles 1a – c with aldehydes 2a – i , ketones 2j – o and an acetal 2p on M. K10 clay at room temperature furnished 3,3′-diindolylalkanes (DIAs: 3a – h , j – r ). The novel formation of tris(3-indolyl)methane 4 from 2i through tandem reactions and of the DIAs 6 and 8 from 1d through Plancher rearrangements were also observed.

Microwave-assisted Michael reactions of 3-(2′-nitrovinyl)indole with indoles on TLC-grade silica gel. A new, facile synthesis of 2,2-bis(3′-indolyl)nitroethanes

Abstract 3-(2′-Nitrovinyl)indole reacted with indole and 1- and 2-alkylindoles on TLC-grade silica gel under microwave irradiation to furnish in 7–10 min bis(indolyl)nitroethanes in high yields (70–86%). The same products were also obtained in 69–84% yields without microwave irradiation, but the reactions required 8–14 h for completion. Skatole was inert under both sets of conditions.

A Facile and Efficient Synthesis of 2,2‐Bis(3′/2′‐indolyl)ethylamines and Three Bisindolic Natural Products

Abstract A simple and efficient synthesis of bis(indolyl)ethylamines and three bisindolic natural products, viz. hallucinogenic 6, genotoxic 7 and the alkanoic acid 8 has been developed by the reaction of indoles with appropriate carbonyl compounds on montmorillonite K10 clay.

DBU, A HIGHLY EFFICIENT REAGENT FOR THE FACILE REGENERATION OF (HETERO)ARYLAMINES FROM THEIR ACETAMIDES AND BENZAMIDES: INFLUENCE OF SOLVENT, TEMPERATURE, AND MICROWAVE IRRADIATION

ABSTRACT 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was found to smoothly cleave the N-acetyl and N-benzoyl derivatives of carbazoles, indoles and nitroanilines quickly in refluxing methanol and the parent amines were recovered in excellent yields. Complete cleavage could also be accomplished in acetonitrile solution under reflux and also under microwave irradiation, which, however, required considerably longer periods.

Influence of steric factors on exciplex energy and magnetic field effect

With the advent of spin chemistry, magnetic field effect (MFE) on exciplex luminescence has emerged as an important domain of research. MFE is a diffusion controlled phenomenon and hence is solvent dielectric (epsilon) dependent. It maximizes at a particular epsilon (epsilon(max)) for a specific exciplex system. Various attempts have been made to explain the variation of this epsilon(max) from one exciplex to another. In our present work we have succeeded for the first time to enmark the energy of exciplex (E(ex)) as the prime factor in determining the epsilon(max). We have indicated a definite inverse correlation (1:1) between epsilon(max) and E(ex). We have also tried to correlate some parameters that are important in exciplex formation, e.g. Chartons steric constant (nu(c)), repulsive energy (R(e)) and E(ex).