Mannich base-connected syntheses mediated by ortho-quinone methides Petra Barta, Ferenc Fülöp and István Szatmári* Review Open Access Address: Beilstein J. Org. Chem. 2018, 14, 560–575. Institute of Pharmaceutical Chemistry and Research Group for doi:10.3762/bjoc.14.43 Stereochemistry, Hungarian Academy of Sciences, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary Received: 06 November 2017 Accepted: 10 February 2018 Email: Published: 06 March 2018 István Szatmári* -
[email protected] Associate Editor: J. A. Murphy * Corresponding author © 2018 Barta et al.; licensee Beilstein-Institut. Keywords: License and terms: see end of document. aminophenols; [4 + 2] cycloaddition; dienophile; Mannich reaction; ortho-quinone methide Abstract This article provides an overview about specifically modified Mannich reactions where the process involves an ortho-quinone methide (o-QM) intermediate. The reactions are classified on the basis of the o-QM source followed by the reactant, e.g., the dieno- phile partner in cycloaddition reactions (C=C or C=N dienophiles) or by the formation of multicomponent Mannich adducts. Due to the important pharmacological activities of these reactive o-QM intermediates, special attention is paid to the biological activity of these compounds. Review Introduction The Mannich reaction is an important, one-pot, multicompo- benzaldehyde and 2-naphthol. This protocol is known as Betti nent, C–C bond forming reaction that is widely used in the syn- reaction and the compound formed as Betti base [7-9]. Several theses of many biologically active and natural compounds [1-5]. examples have been published to extend the reaction and to Originally, the Mannich product is formed through a three-com- synthesize varied substituted aminonaphthol derivatives [10].