A carbene insertion route to β-lactam fused cyclic enediynes

Recent developments in the synthesis of condensed β-lactams

β-Lactams are important heterocycles with diverse pharmacological profiles and have emerged as useful organic synthons.

A nitrilase-mediated entry to 4-carboxymethyl-β-lactams from chemically prepared 4-(cyanomethyl)azetidin-2-ones

4-(Cyanomethyl)azetidin-2-ones were efficiently prepared from 1,2:5,6-di-O-isopropylidene-d-mannitol, followed by a nitrilase-catalyzed hydrolysis to 4-carboxymethyl β-lactams without affecting the sensitive four-membered ring system.

Base-switched annuloselectivity in the reactions of ethyl malonyl chloride and imines

The [2 + 2] and [2 + 2 + 2] annuloselectivity in the reactions of ethyl malonyl chloride with imines was controlled by different bases, providing a simple synthesis of β-lactam-3-carboxylates and 2,3-dihydro-1,3-oxazin-4-ones.

Design, synthesis and RNase A inhibition activity of catechin and epicatechin and nucleobase chimeric molecules

Several novel catechin/epicatechin and nucleobase chimeric molecules 1-6 have been synthesized via azide-alkyne click chemistry. The structures of these hybrids have been confirmed by NMR and mass spectroscopic data. The synthesized molecules were tested for their RNase A inhibition activities. Gel-based assays showed inhibition in micromolar concentrations. The extent of inhibition was found to be dependent upon the nature of base as well as the configuration at C-3 position of catechin.

A novel synthesis of β-lactam fused cyclic enediynes by intramolecular Kinugasa reaction

A general synthetic route to beta-lactam-fused enediynes by intramolecular Kinugasa reaction has been successfully developed. The method has widened the scope of Kinugasa reaction in the synthesis of sensitive systems like the one described in this communication.