The Reactions of Nitrones with Indoles

Indion Ina 225H resin as a novel, selective, recyclable, eco-benign heterogeneous catalyst for the synthesis of bis(indolyl)methanes

“…Literature enumerates various methods for synthesis of bis(indoloyl)methane using protic acids (9Á15), Lewis acids (16Á20), and inorganic compounds. However, most of the methods suffer from drawbacks like long reaction times of 4Á5 days (21), high catalyst loading and use of expensive catalysts (22Á27) or less easily available reagents (28,29), low selectivity (30), use of toxic solvents (31,32), tedious manipulations in the isolation of the pure products (33), unsatisfactory yields, or limited applicability only for aryl aldehydes (34). Furthermore, some of these methods require strictly anhydrous conditions (35Á38).…”

I2-SDS-H2O System: A highly Efficient Dual Catalytic Green System for Deprotection of Imines and in Situ Preparation of Bis(ind

“…This infers the simultaneous involvement of two C=N bonds of bis-anils, leaving behind hydrazine in the reaction mixture. Also, no self-reaction of individual starting materials leading to indole dimer [35] (4) or pyrrole formation [36] (5) were observed under the same reaction conditions (Scheme 1). Optimization of the reaction conditions was undertaken by employing different catalyst loadings under various surfactant conditions.…”

Synthesis and crystal structure of (R, 4R)-3-[(N-benzyl-N-hydroxy-amino)-(1H-indol-3-yl)-methyl]-oxazolidin-2-one

“…So, we have previously shown that N-hydroxylamines, obtained by reaction of nitrones with alkyl 3-lithiopropiolates, could be transformed into the corresponding c-amino a,b-saturated esters [12], c-(Nbenzyl)amino a,b-ethylenic esters and/or a,bethylenic c-lactames [3], c-(N-t-butoxycarbonyl) amino a,b-ethylenic esters [6] and c-(N-tbutoxycarbonyl)amino a,b-dihydroxy esters [15]. The study of the reactivity of nitrones with indolic rings was also carried out [16,17], leading to the development of a synthetic approach of indolic N-hydroxylamines (Fig. 1).…”