Man-Su Tu

Highly selective domino multicyclizations for forming polycyclic fused acridines and azaheterocyclic skeletons.

Highly selective four-component domino multicyclizations for the synthesis of new fused acridines and azaheterocyclic skeletons have been established by mixing common reactants in isobutyric acid under microwave irradiation. The reactions proceeded at fast rates and were conducted to completion within 20-30 min. Up to seven new chemical bonds, four rings, and four stereocenters were assembled in a convenient one-pot operation. The resulting hexacyclic and pentacyclic fused acridines and their stereochemistry have been fully characterized and determined by X-ray structural analysis.

Allylic Amination and N-Arylation-Based Domino Reactions Providing Rapid Three-Component Strategies to Fused Pyrroles with Different Substituted Patterns

New three-component domino reaction providing divergent approaches to multifunctionalized fused pyrroles with different substituted patterns have been established (40 examples). The direct C(sp(3))-N bond formation was achieved through intermolecular allylic amination in a one-pot operation, and N-arylation of amines was realized by varying N-amino acid enaminones. The reaction is easy to perform simply by mixing three common reactants in acetic acid under microwave heating. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good chemical yields.

New domino heteroannulation of enaminones: synthesis of diverse fused naphthyridines

A series of new poly-functionalized fused naphthyridine derivatives were synthesized via a three-component reaction of aldehyde, 2-aminoprop-1-ene-1,1,3-tricarbonitrile and enaminone in EtOH using EtONa as a base. During these reaction processes, the domino construction of fused naphthyridine skeleton with concomitant formation of two new pyridine rings was readily achieved via base promoted three-component reactions in a one-pot operation. The procedures are facile, avoiding time-consuming and costly syntheses, tedious work-up and purifications of precursors.

Regioselective [5 + 1] rearrangement–annulation: a new and efficient domino route to highly functionalized [1,6]naphthyridines

A new [5 + 1] rearrangement–annulation for the regioselective formation of polyfunctionalized [1,6]naphthyridines is described. The new construction of a pyridin-2(1H)-one skeleton and its alkylation on the pyridin-2(1H)-one unit were readily achieved through a novel sequential [4 + 2] cyclization–ring opening–intramolecular cyclization–re-cyclization–elimination of urea process.