A new strategy for the preparation of substituted imidazolidin-2-ones in two steps from readily available N-allylamines is described. Addition of the amine starting materials to isocyanates affords N-allylureas, which are converted to imidazolidin-2-one products with generation of two bonds and up to two stereocenters when treated with aryl bromides and catalytic amounts of Pd2(dba)3/Xantphos in the presence of NaO(t)Bu. [reaction: see text]
