A new ligand can be easily prepared, and its intramolecular dinuclear zinc complexes act as a high performance catalyst for the asymmetric alternating copolymerization of cyclohexene oxide and CO2 under very mild conditions (1 atm CO2 , room temperature), affording completely alternating polycarbonates with up to 93.8 % enantiomeric excess (ee) and 98 % yield. A high Mn value of 28 600 and a relatively narrow polydispersity (Mw /Mn ratio) of 1.43 were also achieved.

A new highly enantioselective domino Michael/hemiketalization reaction of α-hydroxyacetophenone with β,γ-unsaturated α-keto esters for the synthesis of 2,2,4,5-tetrasubstituted chiral tetrahydrofurans is reported. With 2 mol % intramolecular dinuclear zinc-AzePhenol complex prepared in situ from the reaction of multidentate semi-azacrown ether ligand with ZnEt2 , the corresponding anti-multisubstituted tetrahydrofuran products were obtained in up to 90 % yields, and 98 % enantiomeric excess (ee) at 0 °C for 45 min. Moreover, the products were easily converted to 2,3,5-trisubstituted 2,3-dihydrofurans without any loss in optical activity.

No abstract

The reaction of α‐hydroxyacetophenone (II) with a series of β,γ‐unsaturated α‐keto esters under conditions A) affords tetrasubstituted furans (III) with excellent e.e.