Asymmetric alkylations of N-toluenesulfonylimines with dialkylzinc reagents catalyzed by copper-chiral amidophosphine

A study was conducted that includes steric modification of an amidophosphine structure to provide a better catalyst by which alkylationEs of N--toluenesulfonyimine R2 = Tol, along with dimethyl and diisopropylzinc reagents, gives high enantioselectivities. An enolizable N-toluenesulfonyimines that bear alkyl substituents (R1) were also alkylated to the corresponding N-toluenesulfonylamides in high enantioselectivities.