Mass spectrometric support for a bifunctional catalysis mechanism for the base-free Michael addition by a nickel N-heterocyclic carbene complex: Detection of the catalytic intermediates
Abstract A bifunctional catalysis mechanism for an asymmetric base-free Michaeladdition reaction mediated by a chiral nickel N-heterocyclic carbene complex has been corroborated by mass spectrometry. In particular, for the first time, all of the intermediates for a proposed catalytic cycle for an asymmetric base-free Michaeladdition of α-methyl cyano ester and cyclic β-keto ester substrates with