Selenoamides as powerful scaffold to build imidazo[1,5-a]pyridines using a grinding protocol

• Published in: Journal of organometallic chemistry Vol. 919; p. 121315
• Main Authors: Ramírez-Gómez, Antonio, Gutiérrez-Hernández, Alejandro I., Alvarado-Castillo, Miguel A., Toscano, R. Alfredo, Ortega-Alfaro, M. Carmen, López-Cortés, José G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-07-2020
• Subjects: Fischer carbene complex; Iodine; Mechanochemistry; Nitrogen heterocycles; Selenium; Selenium; Nitrogen heterocycles; Mechanochemistry; Fischer carbene complex; Iodine
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2020.121315

We describe the synthetic application of a family of selenoamides [R–C(Se)NHCH2R’ (R = Fc, Aryl, Het, alkyl) tethered to N-heterocyclic motifs (R’ = 2-pyridyl and 2-thiazolyl) obtained from their corresponding Fischer ethoxy carbene complexes [R–C(Cr(CO)5)OEt] using a tandem procedure that involves an aminolysis/seleniurative demetallation. The selenoamides obtained are used as accessible building-block to easily obtain a two-ring fused system with a bridge-head nitrogen atom. This study reveals that CSe bond can be readily and speedily activated with iodine at room temperature, in grinding conditions, for obtaining a family of imidazo[1,5-a]pyridines in good to excellent yields in only 1 min of reaction time. This methodology was successfully extended to the synthesis of ferrocenyl imidazo[1,5-b]thiazole in excellent yield.
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•Selenoamides as potent scaffold to give imidazo[1,5-a]pyridines in excellent yields.•CSe bond can be readily and speedily activated with I2/Py at room temperature.•A grinding procedure allows the synthesis of the target compounds in only 1 min.•A general method for the exclusive formation of imidazo[1,5-a]pyridines.