The halide anions of enantiopure hydrophilic Werner complexes are replaced by BArf−, providing lipophilic catalysts for enantioselective reactions.

The initial energy in a reactive intermediate is derived from the transition state before the intermediate but can affect selectivity after the intermediate. In this way an observable selectivity can report on a prior, kinetically hidden mechanistic step. This new type of mechanistic probe is demonstrated here for the oxidation of 1-methylcyclobutanol by phthaloyl peroxide/Bu4N+Br–, and it supports a hypobromite chain mechanism in place of the previously proposed hydrogen atom transfer mechanism.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adem.202101524.