Asymmetric conjugate additions of chiral phosphonamide anions to α,β-unsaturated carbonyl compounds.: A versatile method for vicinally substituted chirons

Reactions of anions derived from chiral nonracemic allyl, crotyl, and cinnamyl bicyclic C-2-symmetrical phosphonamides with alpha,beta-unsaturated cyclic ketones, esters, lactones, and lactams take place at the gamma-position of the reagents. The products are diastereomerically pure or enriched beta-substituted carbonyl compounds. The method also provides easy access to vicinal substitution of as many as three stereogenic centers including in some cases quaternary carbon atoms, in a one-pot sequence.