Moderne Varianten der Mannich-Reaktion

Abstract

Begehrte Bausteine für die Synthese von Wirk‐ oder Naturstoffen sind Mannich‐Basen und deren Derivate. Moderne Varianten der Mannich‐Reaktion, die die Bandbreite der klassischen intermolekularen Reaktion deutlich erweitern und eine effektive Kontrolle der Regio‐ und Stereoselektivität ermöglichen, sind daher Gegenstand intensiver Forschung. Intramolekulare Reaktionen, insbesondere als Teil von Dominoreaktionssequenzen, führen häufig verblüffend einfach und elegant zu komplexen Zielverbindungen.

Synthesis of Schiff and Mannich bases of news-triazole derivatives and their potential applications for removal of heavy metals from aqueous solution and as antimicrobial agents

“…In the last decade, the Mannich reaction has been highly utilized as one of the potential multi component reactions (MCRs) due to its performance in the building of carbon-nitrogen (C-N) and carbon-carbon (C-C) single bonds. 28 It is well-known that compounds with one active hydrogen atom undergo a single Mannich reaction, while compounds with two neighboring active hydrogen atoms undergo a double Mannich reaction. [29][30][31] Recently, we reported the triple Mannich reaction of 6-amino-2-(ethylthio)pyrimidin-4(3H)-one, which contains three active hydrogen atoms, and the quadruple Mannich reaction of 6-amino-2-thioxo-2,3-dihydropyrimidin-4(1H)-one, which contains four active hydrogen atoms.…”

Stereoselective Mannich Reactions in the Synthesis of Enantiopure Piperidine Alkaloids and Derivatives

“…The electrophilic iminium ion is attacked by the enol tautomer of the carbonyl compound 16 , resulting in the formation of β‐amino‐carbonyl compound 17 . Diastereo‐ or enantioselective formation of the β‐amino‐carbonyl product is a challenge when utilizing the Mannich reaction in the synthesis of complex and chiral piperidines [11] …”

“…For example, preformed electrophiles such as imines or iminium salts can be used, or preformed nucleophiles including enolates, enol ethers and enamines have been developed and of both reaction partners stereodirecting variants are known. These stereodirecting variants of the Mannich reaction provide a distinctly simpler entry into β‐amino‐carbonyl compounds and also provide opportunities to induce asymmetry in the reaction [11] …”

Direct Metal-Free Synthesis of Uracil- and Pentaazaphenalene-Functionalized Porous Organic Polymers via Quadruple Mannich Cyclization and Their Nucleobase Recognition Activities

“…In addition, when the starting molecule has two neighboring active hydrogen atoms, a double Mannich reaction can proceed. , Furthermore, Stevens et al established a quadruple Mannich reaction with 6-aminouracil, which has four active hydrogen atoms . Since the late 1998s, the Mannich reaction has indeed been proposed as a method for producing anticancer medicines . This reaction has recently been utilized in materials science and polymer chemistry, primarily for the production of branching and linear polymeric materials that function as a precursor for carbon materials. − However, to the best of our knowledge, the utilization of quadruple Mannich polycondensation for the synthesis of porous organic polymers bearing uracil groups in their structures has not been reported before.…”