Stereoselective intramolecular radical addition of polyhaloacyl pendant groups to the 1,3-dihydro-2-imidazolone moiety: the chiral synthesis of threo-diaminocarboxylic acids

The intramolecular Ru(II)-catalyzed radical addition of trichloroacetyl and 2,2-dichloro-4-hexenoyl pendant groups to a 1,3-dihydro-2-imidazolone moiety provides a perfectly stereocontrolled approach to the preparation of 1,2-diamines which contain contiguous multi-stereocenters. Typical examples for this approach are given by the chiral synthesis of vicinal-diaminocarboxylic acids, which are amino analogs of statine and MeBmt.