Upjohn dihydroxylation

The Upjohn dihydroxylation is an organic reaction which converts an alkene to a cis vicinal diol.

[1] It is a catalytic system using N-methylmorpholine N-oxide (NMO) as stoichiometric re-oxidant for the osmium tetroxide.

In response to these problems, Stuart Warren and co-workers[2] employed similar reaction conditions to the Sharpless asymmetric dihydroxylation, but replacing the chiral ligands with the achiral quinuclidine to give a racemic reaction product (assuming an achiral starting material is employed).

This approach takes advantage of the fact that when using the Sharpless alkaloid ligands, the dihydroxylation of alkenes is faster and higher yielding than in their absence.

This phenomenon became known as "ligand accelerated catalysis", a term coined by Barry Sharpless during the development of his asymmetric protocol.