Total syntheses of the potent neurotoxins, environmental hazards, and biochemical probes anatoxin-a and homoanatoxin have been achieved from a common intermediate using a combined two-directional synthesis-tandem reaction strategy which includes key advances in oxidative desymmetrisation, tandem Michael-intramolecular Mannich cyclisations and a new method for deprotection of N-tosyl anatoxin-a.

The multicomponent synthesis of α,β-disubstituted N-sulfonyl β-amino esters is described. It involves a zinc-mediated, cobalt-catalyzed three-component reaction between sulfonylimines, acrylates and organic bromides. A possible mechanism is proposed, emphasizing the intermediate formation of an organocobalt as the initiator of a Mannich-like process.

The synthesis of (diarylmethyl)sulfonamides and related compounds by a new manganese-mediated, cobalt-catalyzed three-component reaction between sulfonamides, carbonyl compounds and organic bromides is described. This organometallic Mannich-like process allows the formation of the coupling products within minutes at room temperature. A possible mechanism, emphasizing the crucial role of mangane...

An efficient, two-step construction of highly complex alkaloid-like compounds from the natural product fumagillol is described. This approach, which mimics a biosynthetic cyclase/oxidase sequence, allows for rapid and efficient structure elaboration of the basic fumagillol scaffold with a variety of readily available coupling partners. Mechanistic experiments leading to the discovery of an oxyg...

An enantioselective Brønsted acid catalyzed Mannich reaction between acetophenone derived enamines and N-Boc imines has been developed. Simple diol (S)-H(8)-BINOL has been identified as the optimal catalyst, to afford versatile beta-amino aryl ketones in good yield and enantiomeric excess.

A highly efficient diastereo- and enantioselective Mannich reaction of lactones with a variety of N-Boc-aldimines by using bifunctional rosin-derived amine thiourea catalysts was investigated for the first time, in general, affording the adducts bearing quaternary stereogenic centers with high levels of enantio- and diastereoselectivity (up to 99% ee, and >20:1 dr).

Urea coating has been conducted using polylactic acid (PLA) blended with an industrial softwood kraft lignin. The latter was pre-functionalized via esterification or Mannich reaction. The coated urea becomes therefore a highly effective nitrogen fertilizer due to the controlled release after the coating, the slow release from the organically bound nitrogen structure formed after the Mannich rea...

A highly enantioselective direct Mannich reaction of methyl alkyl ketones with cyclic imines benzo[e][1,2,3]oxathiazine 2,2-dioxides, catalyzed by the combination of cinchona alkaloid derived primary amine and TFA, is disclosed. For unsymmetrical methyl alkyl ketones, it is favoured that specific regioselective addition to the imine substrates occurs at the less-substituted methyl group by ster...

A highly selective and sensitive phenanthroimidazole tagged Mannich base type dizinc(II) fluorescent probe (R-Zn²⁺) has been developed for the pyrophosphate ion (PPi) with a very low limit of detection (LOD) of 0.25 ppm; this also assesses PPi from DNA polymerization chain reaction (PCR).