KIO4 -mediated Selective Hydroxymethylation/Methylenation of Imidazo-Heteroarenes: A Greener Approach
Marcelo Straesser Franco1, Sumbal Saba2, Jamal Rafique3
1Departamento de Química, Universidade Federal de Santa Catarina-UFSC, Florianópolis, 88040-900, SC-Brazil.
Abstract:
Herein, we report a KIO4 -mediated, sustainable and chemoselective approach for the one-pot C(sp2 )-H bond hydroxymethylation or methylenation of imidazo-heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3-hydroxymethyl-imidazo-heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs, e.g., Zolpidem. Furthermore, by using glycerol, bis(imidazo[1,2-a]pyridin-3-yl)methane derivatives were selectively obtained in good to excellent yields.
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