Pedro S Beck, Arthur G Leitão, Yasmin B Santana, José R Correa, Carime V S Rodrigues, Daniel F S Machado, Guilherme D R Matos, Luciana M Ramos, Claudia C Gatto, Sarah C C Oliveira, Carlos K Z Andrade, Brenno A D Neto
This study critically reevaluates reported Biginelli-like reactions using a Kamlet-Abboud-Taft-based solvent effect model. Surprisingly, structural misassignments were discovered in certain multicomponent reactions, leading to the identification of pseudo three-component derivatives instead of the expected MCR adducts. Attempts to replicate literature conditions failed, prompting reconsideration of the described MCRs and proposed mechanisms. Electrospray ionization (tandem) mass spectrometry, NMR, melting points, elemental analyses and single-crystal X-ray analysis exposed inaccuracies in reported MCRs and allowed for the proposition of a complete catalytic cycle...
April 23, 2024: Organic & Biomolecular Chemistry