The Bimolecular Aromatic Mannich Reaction

Multicomponent Reactions with Organoboron Compounds

“…These highly versatile synthetic intermediates can be hydrolyzed to a-amino acids or can be converted to other molecules [11,12]. A number of MCRs having enolate-derived nucleophilic components were subsequently discovered (Scheme 7.3), including the Hantzsch dihydropyridine synthesis [13], the Biginelli reaction [14,15] and the Mannich reaction [16][17][18][19][20]. An added complication in many of these MCRs is the potential irreversible addition of the nucleophile to the carbonyl component, leading to carbonyl addition products.…”

“…Since the products of this process were similar to analogous products obtained from the Mannich reaction among amines, formaldehyde and enolates or electron-rich aromatic rings [17][18][19][20], we have initially termed this process the ''Boronic Acid Mannich (BAM) reaction''. Although initially we considered this process to be a rare example of using alkenyl nucleophiles in a Mannich-like process, the BAM name (which we subsequently stopped using) [24] incorrectly implied a reaction of the alkene moiety of the boronic acid with an intermediate iminium salt 32, similar to bimolecular reactions with enolate equivalents as well as Friedel-Crafts-type reactions of 32 with activated aromatic rings [17]. Thus, additional evidence and further considerations suggested that this transformation apparently proceeds via a novel mechanism.…”

One-Pot Synthesis of Cardanol-Derived High-Efficiency Antioxidants Based on Intramolecular Synergism

“…It is worth mentioning here that the one-pot synthesis of HC-derived biobased antioxidants and their subsequent purification can be carried out under mild conditions, avoiding harsh chemical products. With 3-pentadecyl-phenol as the acidic component, and with water instantly removed by water segregator and proper heating, the Mannich condensation reaction was catalyst-free and favorable to purification. − Usually, aromatic amine can easily turn into a dark color during synthesis, and the purification process is difficult. In this case, simple recrystallization and washing are sufficient to remove impurities from the crude product.…”

Solvent-Free Asymmetric Aminoalkylation of Electron-Rich Aromatic Compounds: Stereoselective Synthesis of Aminoalkylnaphthols by Crystallization-Induced Asymmetric Transformation

“…The precatalyst aminophenol ( R,R )- 12a is an accessible compound generally obtained by stereoselective reduction of the corresponding 2-imidoylphenol . The aminoalkylation of electron-rich aromatic compounds (the aromatic Mannich reaction) is an alternative route to aminonaphthol 3 . Here, we report the results of our work in the straightforward and stereoselective synthesis of aminoalkylnaphthols ( R,R )- 3 (see Scheme ).…”