Organocatalytic Asymmetric Morita-Baylis-Hillman Reaction of Isatins with Vinyl Sulfones.

The organocatalytic asymmetric Morita-Baylis-Hillman (MBH) reaction of isatin derivatives with various vinyl sulfones is disclosed. Chiral sulfone-containing 3-hydroxyoxindoles were produced in good to high yields and with good to high ee's. This report displays an unprecedented example to apply activated alkenes with sulfone moiety other than carbonyl groups in asymmetric MBH reactions and provides an efficient strategy to incorporate the sulfone functional group for the synthesis of chiral 3-hydroxyoxindoles.

Catalytic Asymmetric Addition of Diorganozinc Reagents to Pyrazole-4,5-Diones and Indoline-2,3-Diones.

The catalytic enantioselective diorganozinc additions to cyclic diketones including pyrazolin-4,5-diones and isatins have been developed. In the presence of morpholine-containing chiral amino alcohol ligand, the corresponding chiral cyclic tertiary alcohols were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 95 % ee). The notable feature of this protocol includes its mild reaction conditions, Lewis acid additives free and broad functional group tolerance.