Comparison of metal-carbenoid reactions of β-2-five-membered heteroaryl substituted α,β-unsaturated ketones.

In this study, -2-heteroaryl substituted (-methyl 2-pyrrolyl, 2-thiophenyl, 2-furyl) ,-unsaturated ketones were reacted with two -diazo carbonyl compounds that had different characteristics (dimethyl diazo malonate and 1-diazo-1-phenyl-propane-2-one) in the presence of both copper and rhodium catalysts. In the case of reactions with -methyl 2-pyrrolyl ,-unsaturated ketones, the major product was the insertion derivative. However, in the reactions of 2-thiophenyl and 2-furyl ,-unsaturated ketones with dimethyl diazomalonate (acceptor-acceptor disubstituted), only dihydrofuran products were formed over carbonyl ylides.

The Rhodium(II) Carbenoid Cyclization-Cycloaddition Cascade of alpha-Diazo Dihydroindolinones for the Synthesis of Novel Azapolycyclic Ring Systems.

Tandem carbonyl ylide formation-1,3-dipolar cycloaddition of alpha-diazo N-acetyl-tetrahydro-beta-carbolin-1-one derivatives occur efficiently in the presence of a dirhodium catalyst to afford bimolecular cycloadducts in high yield. The Rh(II)-catalyzed reaction also takes place intramolecularly to give products derived from trapping of the carbonyl ylide dipole with a tethered alkene. The power of the intramolecular cascade sequence is that it rapidly assembles a pentacyclic ring system containing three new stereocenters and two adjacent quaternary centers stereospecifically in a single step and in high yield.

Synthesis and investigation of tuberculosis inhibition activities of some 1,2,3-triazole derivatives.

In this study, alpha-diazo-beta-oxoaldehyde compounds were condensed with different amines to yield 4-acyl-1H-1,2,3-triazole derivatives. The 1,2,3-triazole compounds were investigated for their inhibition activities against tuberculosis.