For 10 points, name this property measuring the ability of a molecule to donate electron pairs in a chemical reaction, contrasted with electrophillicity.
Due to steric hindrance, this property is lacked by LDA and a compound named for Hünig, making them useful for creating enolates. When a molecule with this property reacts with a carbonyl alpha to a stereocenter, the product stereochemistry can be determined using the Felkin-Anh model. Compounds with this property can be used to open aziridines and epoxides. Stereochemical (*) inversion occurs in a reaction mechanism describing how a compound with this property displaces a leaving group in a single step. Compounds with this property, which often correlates with basic strength, participate in namesake bimolecular substitution reactions. For 10 points, name this property measuring the ability of a molecule to donate electron pairs in a chemical reaction, contrasted with electrophillicity.
Due to steric hindrance, this property is lacked by LDA and a compound named for Hünig, making them useful for creating enolates.
nucleophilicity [accept word forms like "nucleophiles"]