Chiral nickel complexes of isoquinox catalyze an asymmetric reductive alkenylation of N-picolyl aldimines with readily available alkenyl bromides, triflates, and tosylates as carbon electrophiles. The method features neutral and mild conditions, ready scalability with low loadings of nickel catalysts, and excellent compatibility with polar groups and nitrogen-containing heterocycles. Mechanistically, DFT calculations reveal that alkenyl transfer proceeds through a mechanism of "elementary 1,4-addition" to N-picolyl imines involving six-membered cyclic transition states.
Zhao et al. (Wed,) studied this question.