Highly diastereo- and enantioselective Michael addition of 3-substituted benzofuran-2(3H)-ones to 4-oxo-enoates catalyzed by lanthanide(iii) complexes

An efficient lanthanide(III)-catalyzed diastereo- and enantioselective Michael addition of 3-substituted benzofuran-2(3H)-ones to 4-oxo-enoates was developed. The desired adducts with contiguous quaternary-tertiary stereocenters were obtained in up to 99% yield with up to >95/5 dr and 98% ee.