Dioxazaborocanes: old adducts, new tricks

Dioxazaborocanes are boronic adducts obtained by condensation of diethanolamine derivatives with boronic compounds. They were first described in the mid-1950's as a practical way to isolate a boronic adduct. Their use has for a long time been restricted to this purpose for the isolation and characterisation of either a final product or a boronic intermediate. Only recently have they been directly involved in chemical transformations in which they proved equivalent or superior to their acid counterpart. In the meantime they have also been used as protected boronic acids. We wish to show in this report that they will likely represent a fluoride-free alternative to organotrifluoroborate salts and therefore an area of intense development.