The sulfation reaction using sulfur trioxide amine/amide complexes is the most commonly used method for alcoholic or phenolic groups in carbohydrates, flavonoids, steroids, proteins, and aliphatic or alicyclic scaffolds. Ball and co-workers have successfully used a sulfur trioxide trimethylamine complex (Me3N•SO3) and a lipophilic cation-exchange to access Avibactam®, a sulfate containing β-lactamase inhibitor. They reported a simultaneous one-pot deprotection and sulfation reaction of a hydroxylamine intermediate using the Me3N•SO3 complex. The resulting intermediate was ion exchanged with tetrabutylammonium acetate (TBAOAc) making it more lipophilic and therefore facilitates the extraction of the organosulfate intermediate into DCM. Finally, a lipophilic sodium salt exchange reagent, sodium-2-ethyl-hexanoate (NEH) was added affording Avibactam® in 90% yield as the sodium salt (Scheme 5). Scheme 5. The final sulfation steps of Avibactam® total synthesis. The Me3N•SO3 complex was reported for the site selective sulfation of polysaccharides including pyranoside scaffolds. The site selective sulfation of pyranoside scaffolds was carried out under catalytic conditions using diarylborinic acids are highly active catalyst for several reactions including sulfation. This method will lead to the sulfation of different OH group positions including cis-1,2-diol and 1,3-diol pyranoside derivatives. β-thioglycoside pyranoside was selected as a model for the site selective sulfation using Me3N•SO3 and the addition of diarylborinic acid and DIPEA was critical to improve the isolated yield (Scheme 6). Scheme 6. Site selective sulfation of pyranoside scaffolds catalysed by diarylborinic acids (a).