[show abstract][hide abstract] ABSTRACT: A dinuclear zinc-ProPhenol catalyst enables highly enantioselective nitro-Michael reactions with oxazol-4(5H)-ones as nucleophilic substrates (see scheme, Nap = 2-naphthyl). This work highlights the utility of the ProPhenol family of ligands. The modular nature of these ligands proved crucial in the optimization of reaction conditions to achieve excellent stereoselectivities.
Angewandte Chemie International Edition 05/2012; 51(26):6480-3. · 13.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: A highly diastereo- and enantioselective formal [3 + 2] cycloaddition of α,β-unsaturated esters and 3-hydroxyoxindoles catalyzed by a dinuclear zinc-ProPhenol complex is reported. The stereoselective Michael additions of 3-hydroxyoxindoles and the subsequent transesterifications afford spirocyclic δ-lactones.