Dirhodium(II) Tetrakis[alkyl 2-oxaazetidine-4(S)-carboxylates]. A New Set of Effective Chiral Catalysts for Asymmetric Intermolecular Cyclopropanation Reactions with Diazoacetates - Doyle, Michael P; Zhou, Qi-Lin; Simonsen, Stanley H; Lynch, Vincent (Synlett, 1996)