title: Facts, presumptions, and myths on the solvent-free and catalyst-free Biginelli reaction. What is catalysis for?
abstract: The current manuscript describes the role and importance of catalysis and solvent effects for the Biginelli multicomponent reaction. The overwhelming number of new catalysts and conditions recently published for the Biginelli synthesis, including in some manuscripts entitled "catalyst-free" and/or "solvent-free" have incentivized controversies and hot debates regarding the importance of developing new catalysts and reaction conditions to perform this very important multicomponent reaction. These so-called "catalyst-free" reports have generated much confusion in the field, requiring urgent elucidations. In this manuscript, we exemplify, demystify, and discuss the crucial role of catalysis, solvent effects, mechanisms, kinetics, facts, presumptions, and myths associated with the Biginelli reaction aiming to avoid current and future confusion and to stimulate new approaches.
authors.affiliation: Laboratory of Medicinal and Technological Chemistry, University of Brasília, Chemistry Institute (IQ-UnB) , Campus Universitário Darcy Ribeiro, P.O.Box 4478, Brasília, Distrito Federal CEP 70904-970, Brazil.
authors.forename: Haline G O
authors.initials: HG
authors.lastname: Alvim
authors.forename: Tatiani B
authors.initials: TB
authors.lastname: Lima
authors.forename: Aline L
authors.initials: AL
authors.lastname: de Oliveira
authors.forename: Heibbe C B
authors.initials: HC
authors.lastname: de Oliveira
authors.forename: Fabricio M
authors.initials: FM
authors.lastname: Silva
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Gozzo
authors.forename: Roberto Y
authors.initials: RY
authors.lastname: Souza
authors.forename: Wender A
authors.initials: WA
authors.lastname: da Silva
authors.forename: Brenno A D
authors.initials: BA
authors.lastname: Neto
mesh_terms: D002384:Catalysis; D007700:Kinetics; D015394:Molecular Structure; D011744:Pyrimidinones / Q000737:chemistry*; D012997:Solvents
chemical_list: D011744:Pyrimidinones; D012997:Solvents