Formaldehyde SAMP-Hydrazone as a Neutral Chiral Formyl Anion and Cyanide Equivalent: Asymmetric Michael Additions to Nitroalkenes - Enders, Dieter; Syrig, Ralf; Raabe, Gerhard; Fernández, Rosario; Gasch, Consolación; Lassaletta, José-María; Llera, José-Manuel (Synthesis, 1996)