Synthesis of Novel Indoles and Bisindolylmethanes: Approaches to Structures with Biological Activity

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Natural deep eutectic solvents in the hetero-Diels-Alder approach to bis(indolyl)methanes

Publication . Grosso, Carla; Brigas, Amadeu; de los Santos, Jesus M.; Palacios, Francisco; Lemos, Americo; Pinho e Melo, Teresa M. V. D.

For the first time, the use of natural deep eutectic solvents (NADES) as reaction media to carry out hetero-Diels-Alder reactions is disclosed. This allowed to improve the efficiency and sustainability of the synthetic approach to bis(indolyl)methanes (BIMs) based on bis-hetero-Diels-Alder/conjugate addition reactions of nitroso- and azoalkenes with indoles. The ternary mixture of H2O with choline chloride/glycerol allowed the tuning of the physical properties of this NADES leading to a better solvent system, affording the target hydroxyiminomethyl- and hydrazonomethyl-BIMs, in much shorter reaction times, higher efficiency and easier isolation procedures. Furthermore, the direct access to carbonyl-BIMs was possible when 3-methyl-1-tert-butoxycarbonyl azoalkenes were used. [GRAPHICS] .

2019-07Journal article

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Selective synthesis of 3-(1H-Tetrazol-5-yl)-indoles from 2H-Azirines and Arynes

Publication . Grosso, Carla; Alves, Cláudia; Sase, Terver J.; Alves, Nuno G.; Cardoso, Ana L.; Melo, Teresa M. V. D. Pinho e; Lemos, Americo

A new selective synthetic approach to indole derivatives bearing a tetrazole moiety has been developed. Arynes, generated in situ from o-(trimethylsilyl)aryl triflates and KF, reacted smoothly with 2-(2-benzyl-2H-tetrazol-5-yl)-2H-azirines to give 3-(2-benzyl-2H-tetrazol-5-yl)-indole derivatives with high selectivity. Deprotection of the tetrazole moiety gave 3-(1H-tetrazol-5-yl)-indole derivatives.

2024-06-24Journal article

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